STUDIES ON THE ACTION OF DIURETICS

I. THE EFFECT OF EUPHYLLIN AND SALYRGANUPONGLOMERULARFILTRATION ANDTUBULARREABSORPTION'

BY HENRYLENZENSCHMITZ(From the Lasker Foundation for Medical Research and the Department of Medicine,

University of Chicago, Chicago)

(Received for publication May 3, 1932)

Since the appearance in 1887 of von Schroeder's first publication (1)concerning the action of xanthine diuretics there has been much debateregarding the mechanism by which these substances produce diuresis.Similarly there has been considerable controversy as to the manner inwhich salyrgan and other organic mercury compounds increase the outputof urine.

REVIEW OF LITERATURE

In the earlier work on xanthine diuresis investigators were chiefly interestedin distinguishing between direct action on the renal cells and effects producedthrough changes in renal circulation. Von Schroeder (1) (2) concluded fromhis experiments that the effect of caffeine and related substances upon urineoutput was independent of circulatory changes. Loewi, Fletcher and Hender-son (3) held the opposite point of view. They confirmed the observation, firstmade by Phillips and Bradford (4), that caffeine usually increases the volumeof the kidney and considered this as evidence that diuresis was caused bydilatation of the renal blood vessels. Although this observation concerningkidney volume during caffeine diuresis is generally accepted, its significance hasbeen questioned by Gottlieb and Magnus (5) because diuresis sometimesoccurs without increase in kidney volume, by Brings and Molitor (6) who con-cluded that the increase in volume was of too short duration to be significant,and by Cushny (7) who pointed out that increase in kidney volume does notnecessarily indicate vasodilatation.

It has been demonstrated by direct measurement that there is usually anincrease in renal blood flow following the administration of the xanthinediuretics. However, the evidence seems to indicate that the diuresis is inde-pendent of this. Cushny and Lambie (8), E. Schmidt (9), Ozaki (10), andR. Schmidt (11) have reported that the acceleration in rate of blood flow is ofshort duration and that diuresis may begin before the increase occurs and persistafter the flow has returned to normal. Richards and Plant (12) demonstratedthat caffeine increased the output of the perfused rabbits' kidney when the rateof blood flow was kept constant, and Gremels (13) (14), working with a Starlingheart-lung-kidney preparation, obtained diuresis with caffeine, theobromineand theocin when increase in rate of flow was prevented by previously dilatingthe renal vessels to a maximum. Miwa and Tamura (15) found no increase

I The major part of this work was reported at the 1931 meeting of TheAmerican Society for Clinical Investigation.

1075

ACTION OF DIURETICS

in renal blood flow during caffeine diuresis, and Hartwich (16) observed diuresisin the isolated kidney of the frog perfused with Ringer's solution, withoutincrease in rate of perfusion flow. Dreyer and Verney (17) have presentedevidence that the rate of urine flow is independent of the velocity of blood flow.

These observations do not, however, dispose of the possibility that xanthinediuresis is related to changes in the renal vessels. Richards and Schmidt (18)observed, during direct microscopic study of the frog's kidney, that caffeineconsiderably increased the number of functioning glomeruli and the number ofpatent capillary loops in individual glomeruli. Richards and his co-workers(19) (20) (21) have also presented evidence that chemical substances mayconstrict the vas efferens of the frog's glomerulus to a greater degree than thevas afferens. It is conceivable, as Verney and Winton (22) have pointed out,that caffeine increases intraglomerular pressure by dilating the afferent vesselsto a greater extent than the efferent vessels, this increase in glomerular capillarypressure not necessarily being accompanied by an increase in rate of bloodflow during the whole of diuresis. In support of this hypothesis Verney andWinton have shown, in experiments with the heart-lung-kidney preparation,that increase in perfusion pressure and caffeine produces the same changes inthe composition of the urine and that caffeine in large doses regularly producesan increase in rate of blood flow through the kidney.

Von Schroeder, convinced that the increase in urine flow caused by thepurine derivatives was independent of circulatory changes, attributed thediuresis to stimulation of the renal cells to greater secretory activity. Gottlieband Magnus (5), Schmidt (11), Barcroft and Straub (23), Gremels (24),Wohlenberg (25) and others expressed similar views. In support of this theoryit has been maintained by Barcroft (23) (26) and Gremels (24) that an increasein oxygen consumption occurs. However, Miwa and Tamura (15) and Hay-man and Schmidt (27) found no evidence of increased metabolism and Masuda(28) observed that caffeine action persisted in the presence of potassium cyanide.Wohlenberg (25) stated that the action of weak caffeine and theophyllinsolutions on the perfused frog's kidney could be prevented by asphyxiation ornarcotization of the metabolic processes occurring in the glomeruli. Sincelarger doses of the diuretics were effective in spite of such asphyxiation andnarcotization he was forced to admit the possibility of other factors such asincreased permeability of the glomerular membrane.

Sobierafnski (29) reported that indigotate stained the tubular epitheliumless than normally during caffeine diuresis, and maintained that the purinederivatives acted by inhibiting reabsorption in the tubules. This observationcan just as readily be explained on the basis that a more rapid flow of fluid downthe tubules afforded less opportunity for diffusion of the dye into the tubulecells. Tashiro and Abe (30) repeated Sobierafnski's experiments and obtainedsimilar results, but Teploff (31) found no evidence that theocin had any in-fluence upon the extent to which the cells of the renal tubules were stained bycarmine.

Cushny (7) agreed that the purine derivatives had a direct action on therenal cells but suggested on the basis of his " Modern Theory" of urine secretionthat the permeability of the capsule was increased and the resistance to filtra-tion thus reduced. Brtihl (32) conducted experiments with collodion mem-branes, the pores of which were filled with albumin to simulate the capsule.He reported a reversible increase in permeability in the presence of caffeine andconsidered this due to a change in the dispersion of the protein molecules inthe pores.

In recent years many investigators have attributed the action of the

1076

HENRYLENZEN SCHMITZ

xanthine diuretics to extra-renal factors. Veil and Spiro (33) and Ellinger,Heymann and Klein (34) (35) reported that caffeine increased the capacityof blood serum for ultrafiltration, and proposed that the purines reduced theaffinity of the proteins for water. Faludi (36) was unable to confirm thisobservation and Meyer (37) recently reported that euphyllin increased thewater binding power of the blood.

Asher and his pupils maintain that the xanthine diuretics act by increasingthe permeability of the tissues, the response on the part of the kidneys beingsecondary to an increase of chloride and other electrolytes in the blood stream.This theory receives its principal support from the observation made by Curtis(38) (39) (40) (41) that the diuretic action of euphyllin is decreased by thesimultaneous intraperitoneal injection of isotonic or hypotonic sucrose solution,and is blocked almost completely by a similar injection of distilled water, theseinjections preventing the slight increase in plasma sodium chloride concentra-tion which was observed in control experiments and which was considered theprime factor in stimulating the kidney to greater activity. Hartwich (42)found, on the other hand, that the intraperitoneal injection of hypertonic saltsolution, which presumably withdrew water from the blood, did not preventeuphyllin from producing diuresis. Riesen (43) reported that euphyllinincreased the electrolyte concentration of an artificial fluid perfused throughthe intestines of the frog. The observations made by Nakao (44) (45) andRaulston (46) are of interest but do not lend much support to the Asher theory.

It is difficult to understand how a change in tissue permeability can increasethe electrolyte concentration of the plasma. It would be more logical to assume

that a shift of water and salt from the tissues to the plasma occurred as theresult of an increase in hydrogen ion concentration. The fact that the xanthinediuretics produce diuresis when the kidneys are isolated from the other tissues(11) (13) (16) (22) makes such an assumption unnecessary. Buichler (47)conceded that the "specific diuretics" had a direct renal action since diuresisoccurred in the isolated kidney of the frog, but concluded that this renal actionplayed an insignificant r6le because the amount of diuretic necessary to producethe effect was large and the resulting increase in urine output was small.

Meyer's report (37) that the colloid osmotic pressure of the blood is in-creased after the intravenous injection of euphyllin has been referred to above.He also expressed the opinion that euphyllin had both a renal and an extra-renal action. Molitor and Pick (48) concluded from their experiments thatthe purines acted through the medium of a center in the hypothalamus whichregulated the water exchange.

In the case of the organic mercury compounds most investigators havedirected their attention to changes in the chemistry of the blood and urineduring diuresis in an effort to prove or disprove the extra-renal action of thesesubstances. Saxl and Heilig (49) were the first to call attention to the factthat novasurol causes a relative as well as an absolute increase of sodium chlo-ride in the urine. This observation has been generally confirmed. The con-

centration of urea, on the other hand, decreases and the absolute amountshows no significant change (Saxl and Heilig (49), Crawford and McIntosh (50),Keith and Whelan (51), Melville and Stehle (52)). Keith and Whelan (51)also reported that there was no appreciable change in the amount of calcium,phosphorus or sulphate excreted in the urine while potassium and magnesium

showed a slight increase. This marked increase in excretion of sodium chloridewithout significant change in the other constituents of the urine has led many

investigators to believe that the primary action of novasurol is an extra-renalmobilization of salt and water. Sometimes the concentration of chloride in

1077

ACTION OF DIURETICS

the urine rises to a value above that in the plasma. Moller (53) concludedthat this could only be explained by a direct action on the kidneys although heagreed, on the basis of other findings, that mercurial diuretics also had anextra-renal effect.

Studies of the blood electrolytes indicate that no significant changes occurfollowing the administration of the mercurial diuretics. Nonnenbruch (54)and Moller (53) found no change in the concentration of sodium chloride whileSaxl and Heilig (55) reported an initial increase followed quickly by a fall.Crawford and McIntosh (50) observed a slight decrease in the concentrationof sodium chloride but found no change in the urea. Keith and Whelan (51)stated that changes in the blood were inconstant and never marked. Noguchi(56) reported that the concentration of potassium in the serum was considerablyincreased. He found a similar increase in potassium during the ingestion oflarge amounts of water and considered this significant.

Many investigators have studied the concentration of protein in the plasmaas a measure of the presence or absence of hydremia. The reports are con-flicting and one gets the impression on reviewing the work that too much sig-nificance has often been attached to slight changes. Saxl and Heilig (49) intheir original publication stated that they often found a decrease in the con-centration of protein in the plasma subsequent to the injection of novasurolbut that this did not occur regularly. Later they reported experiments onnormal dogs in which they found an early decrease in concentration with asubsequent rise (55). Bohn (57) (58) also reported a prompt fall in proteinconcentration after the administration of novasurol. This fall lasted only ashort time and was followed by an increase in concentration which he con-sidered due to secondary factors. Bohn and Saxl and Heilig concluded thatthe action of novasurol was of an extra-renal nature. The findings of Crawfordand McIntosh (50) were similar to those quoted above but were interpretedsomewhat differently. These authors felt that the drug acted not only on theextra-renal tissues but also on the kidneys, the action on the kidneys being theimportant one during the greater part of the diuresis. Serby (59) came to thesame conclusion largely on the basis of plasma protein determinations in onecase. Muihling (60), on the other hand, reported a primary increase and alater fall in concentration and concluded that the primary action was on thekidneys, which responded with an increase in excretion of water and sodiumchloride with the result that salt and water were secondarily drawn from thetissues into the blood. Nonnenbruch (54) observed an increase in plasmaprotein concentration. Since the erythrocyte count was unchanged he con-sidered this increase absolute and not due to loss of water from the blood.Bleyer (61) could demonstrate no constant change. A definite fall in con-centration occurred in only one of his nine experiments. In six of the remainingthere were slight increases or decreases not exceeding the limits of error of themethod employed.

During a certain stage of uranium nephritis Saxl and Heilig (55) observed amarked fall in the plasma proteins, following the injection of novasurol, whichpersisted for hours. This they considered evidence of extra-renal action, themobilized salt and water remaining in the blood because the damaged kidneyswere unable to excrete them. Bohn (57) obtained similar results in experimentson nephrectomized rabbits and Moller (53) reported that salyrgan caused a fallin hemoglobin and an increase in serum chloride when administered to animalsafter removal of the kidneys. The normal water metabolism is so disturbed inexperiments of this nature that one wonders whether it is justifiable to drawany conclusions.

1078

HENRYLENZEN SCHMITZ

Feh6r (62) determined the blood volume by means of the trypan red methodand reported a marked increase three hours after the administration of salyrgan.Since a considerable interval necessarily intervened in each instance betweenthe control determination and the determination after salyrgan other factorsmay have contributed to the changes observed.

Tezner (63) studied the absorption time of subcutaneously injected normalsaline solution. He found that the solution was absorbed with somewhatgreater rapidity after the administration of novasurol, and interpreted this asevidence that salt and water were being mobilized for excretion. This phenom-enon can also be accounted for by a primary renal action.

Recht (64) and Brunn (65) also supported the theory that the mercurialdiuretics act primarily on the extra-renal tissues. Meyer (66) reported thatthe colloid osmotic pressure of the blood usually decreased after the injectionof salyrgan and then with the onset of diuresis rose again above the controlvalue. In some instances, an immediate increase was observed. He was ofthe opinion that salyrgan decreased the water binding power of the extra-renaltissues but believed that it also had a direct, but less significant, renal action.Fodor (67) concluded that novasurol acted neither directly on the kidneys noron the tissues, but on a hypothetical center in the medulla which regulated thewater and chloride metabolism.

The evidence presented by Gremels (14), Schmidt (11) and Govaerts (68)indicates that the mercurial diuretics act directly on the kidneys. Gremelsdemonstrated that good diuresis could be obtained from salyrgan and novasurolin the Starling heart-lung-kidney preparation, and Schmidt observed an increasein urine flow from the kidneys of frogs perfused with colloid-free solutions.Govaerts attacked the problem in a very ingenious manner by transplantingkidneys from one animal into the neck of another. When the kidneys froman animal previously given an intravenous dose of novasurol were connectedwith the circulation of an animal which had received no diuretic, the trans-planted kidneys produced an increased amount of urine while the animal's ownkidneys continued to excrete urine at a normal rate. When the converseexperiment was tried, the transplanted kidneys in the neck put out a normalamount of urine while the animal's own kidneys showed a diuresis.

No correlation between novasurol or salyrgan diuresis and blood flowthrough the kidneys was found by Gremels, Schloss (69) or Schmidt. Anincrease in oxygen consumption was reported by Gremels, who concluded thatthese substances acted directly on the kidneys by stimulating secretion. Kulcke(70) expressed the view that novasurol acted on the tubule cells, small amountsstimulating the secretory function, larger amounts injuring and destroying thecells, as in bichloride poisoning.

From this review of the literature it is obvious that further evidenceregarding the mechanisms by which these diuretics increase the output ofurine is desirable.

In 1926 Rehberg (71) proposed a method for measuring glomerularfiltration and tubular reabsorption. This method is based upon thepremises that urine is formed in mammals by a process of filtration andreabsorption and that creatinine is a non-threshold substance and henceis not reabsorbed in the tubules. These premises are well substantiatedby the work of Richards, Rehberg, Ekehorn (76) and others to whosepublications the reader is referred. From this starting point Rehberg

71

1079

ACTION OF DIURETICS

reasoned that the concentration of creatinine in the urine times the urinevolume must equal the concentration of creatinine in the glomerularfiltrate times the volume of the glomerular filtrate. Since glomerularfluid is a protein-free filtrate of the plasma, the concentration of creatininein the plasma may be substituted for the concentration of creatinine inthe glomerular filtrate. By parallel determinations of creatinine in theplasma and in the urine it is thus possible to calculate the amount ofglomerular fluid formed per unit of time. The amount of reabsorptionoccurring in the tubules is then determined by subtracting the urinevolume from the amount of glomerular filtrate.

In the experiments reported below, this method of Rehberg has beenemployed to investigate the influence of euphyllin and salyrgan uponglomerular filtration and tubular reabsorption. Chrometzka and Unger(72) have recently published the results of similar experiments.

PROCEDURE

The experiments were performed upon eight female dogs weighingbetween ten and thirteen kilos. Food was withheld from the animals forfifteen hours preceding the experiment. Three hours before the beginningof the experiment proper 3 grams of creatinine in 50 cc. of water weregiven by stomach tube. This sufficed to raise the initial concentrationof creatinine in the plasma to values ranging from 5 to 10 or more mgm.per 100 cc. and thus made the determinations more accurate. During thecourse of the experiment the amount of creatinine in the plasma steadilydecreased. Hence a fairly accurate average concentration for each periodof observation could be obtained. The animals were allowed no water forat least one hour preceding the experiment. At the end of this periodthe absorption of any water previously present in the alimentary tracthad, as a rule, produced its maximum effect upon the urine output. Thefluid intake preceding this period of abstinence was varied considerably inorder to vary the initial urine volume. In some instances water waswithheld entirely except for the small amount given along with thecreatinine. In other experiments water was permitted ad libitum.Whenlarge initial urine volumes were desired, water was given by stomachtube in amounts as high as 200 cc. per hour.

During the experiment proper urine collections were made for suc-cessive periods before and after the administration of the diuretic to bestudied. These collections were made directly into accurately graduatedcylinders by means of a stiff rubber catheter inserted into the bladderthrough the urethra. The catheter was left in place throughout theexperiment. Toward the end of each period it was moved about toassure as complete emptying of the bladder as possible.

In some experiments blood samples were obtained at the middle ofeach period of urine collection. Usually, however, fewer blood specimens

1080

HENRYLENZEN SCHMITZ

were taken and the concentration of creatinine corresponding to themiddle of each period was then obtained by graphing the known values.The creatinine determinations were made by the method of Folin (73).Both euphyllin and salyrgan were given intravenously. The salineinjections were made by the gravity method.

As a rule, two or more control periods of ten minutes each were

obtained before the. diuretic was administered. When the initial urinevolume was quite small a single long control period was used. When theurine volume showed a tendency to increase during the control periodsthe administration of the diuretic was postponed until the urine outputbegan to decrease. In addition to these control periods preceding theadministration of diuretics several control experiments were performed.

The results of the experiments are presented in the accompanyingtables and graphs. For purposes of comparison the urine volumes andrates of glomerular filtration are expressed in terms of cubic centimetersper minute. The amount of fluid reabsorbed in the tubules per minuteis expressed as the per cent of the corresponding volume of filtrate.

ControlsThe variations in glomerular filtration and in tubular reabsorption

which occurred during successive periods of observation under the condi-tions of the experiment are shown in Table 1. The changes in filtration

TABLE 1

Spontaneous variations in glomerular fitration and tubular reabsorption

Change in ChangeReabsorption glomerular in

Dog Time Urine Glomerular of watio filtration reabsorptionnumber volume filtration in tubules

Increase Dese Increase Decrease

cc. per cc. per per cc. per cc. per per perminute minute cent minute minute cent cent

100 2:27-2:37 2.2 76.0 97.12:37-2:47 1.3 62.5 97.9 13.5 0.82:47-2:57 0.9 63.0 98.5 0.5 0.62:57-3:07 0.95 72.0 98.6 9.0 0.13:07-3:17 0.98 66.5 98.5 5.5 0.13:17-3:27 1.02 58.5 98.3 8.0 0.2

101 1:56-2:06 3.4 66.5 94.92:06-2:16 2.35 54.0 95.6 12.5 0.72:16-2:26 1.55 56.0 97.2 2.0 1.62:26-2:36 1.45 56.5 97.4 0.5 0.22:36-2:46 1.25 50.5 97.5 6.0 0.1

102 2:12-2:22 3.6 68.5 94.72:22-2:32 4.1 71.5 94.2 3.0 0.52:32-2:42 3.6 62.0 94.2 9.52:42-2:52 3.1 55.0 94.3 7.0 O0.2:52-3:02 2.9 51.5 94.4 3.5 0.1

1081

ACTION OF DIURETICS

TABLE 1 (continued)

Urine Glomerular Reabsorptionvolume filtration in wtules

cc. perminute

1.81.351.2

4.75.14.12.45

1.360.90.35

1.551.421.351.0

0.180.170.16

2.12.251.81.64

3.33.453.55

0.50.60.250.12

3.353.12.752.4

2.32.01.851.07

1.731.931.331.33

cc. perminute

59.053.050.5

142.0137.0129.5121.5

101.075.056.0

81.564.564.062.5

91.081.085.0

56.558.557.058.0

96.089.596.5

35.022.020.034.0

80.075.071.069.5

69.566.055.054.0

44.041.046.543.0

percent

96.997.497.6

96.796.396.897.9

98.798.899.4

98.197.897.998.4

99.899.899.8

96.396.196.897.2

96.596.196.3

98.697.398.799.6

95.895.896.196.5

96.796.996.698.0

96.195.397.196.9

Change inglomerular

filtration

Increase Decrease

cc. per cc. perminute minute

4.0

2.0

1.0

7.0

14.0

5.5

Changein

reabsorption

Increase Decrease

per percent cent

6.0 0.52.5 0.2

5.07.58.0

0.51.1

26.0 0.119.0 0.6

17.00.51.5

10.0

1.5

6.5

13.02.0

5.04.01.5

3.511.0

1.0

3.0

3.5

0.1o.5

0.70.4

0.2

1.40.9

0.30.4

0.2

1.4

1.8

0.4

0.3

0.2

0.4

1.3

0.3

0.8

0.2

Dognumber

102

103

103

104

104

105

105

106

106

106

107

Time

2:08-2:182:18-2:282:28-2:38

2:06-2:162:16-2:262 :26-2 :362:36-2:46

2:14-2:252:25-2:352:35-2:45

1:06-1:161:17-1:271:27-1:371:37-1:47

2:05-2:252:25-2:452:45-3:05

2:15-2:252:25-2:352:35-2:452:45-2:55

2:25-2:352:35-2:452:45-2:55

1:47-2:022:02-2:172 :17-2 :372:37-2:58

3:32-3:423:44-3:553:55-4:054:05-4:15

2:03-2:132:13-2:232:23-2:332:33-2:43

2:00-2:152 :15-2:302 :30-2 :452:45-3:00

1082

HENRYLENZEN SCHMITZ

represent not only actual increases or decreases in rate of formation butalso the variations resulting from experimental errors such as thoseoccurring in the creatinine determinations. Of primary interest areincreases in filtration and decreases in reabsorption, the two factorswhich tend to augment urine output. Increases in filtration occurredinfrequently and seldom were significant. The maximum observed was14 cc. per minute. Decreases in the percentage of reabsorption in thetubules were also uncommon. The largest decrease was 1.3. In themajority of instances, decreases in filtration and increases in percentagereabsorption occurred, both of these factors tending to diminish the urinevolume.

Euphyllin experimentsThe experiments with euphyllin may be divided into two groups,

those in which diuresis was obtained, and those in which no increase inurine output occurred. The results of the former group are presented inTable 2 and Figure 1.

Euphyllin diuresis was characteristically associated with an increasein the calculated rate of glomerular filtration. In a few experiments themaximum rate of filtration immediately preceded the maximum urinevolume. In experiments 57 and 58 diuresis persisted after the rate offiltration had returned to normal. Changes in reabsorption were vari-able. In experiments 1, 4 and 14 the percentage reabsorption wasdefinitely increased. In four other experiments (34, 50, 63 and 64) therewas no significant change during the course of the diuresis. In only threeinstances were there decreases in reabsorption which definitely exceededthe maximum observed in the controls. However, the occurrence ofdecreases was more frequent than in the control experiments and in anumber of instances decreased reabsorption contributed considerably tothe increase in urine output.

The urine output after the intravenous injection of 2 cc. of euphyllinonly twice exceeded 2 cc. per minute. As a rule diuresis began withinfive minutes after the administration of the drug.

Practically all of the failures to obtain diuresis with euphyllin occurredin experiments in which the urine volume to begin with was 1 cc. perminute or greater. In fifteen of seventeen experiments in which thecontrol urine volumes were below 1 cc. per minute the injection ofeuphyllin was followed by diuresis. In four experiments with initialurine volumes ranging between 1 cc. and 1.4 cc. per minute, the responseto euphyllin was variable. In six experiments with control urine volumesgreater than 1.5 cc. per minute, there was a decrease in urine volumefollowing the injection of euphyllin. In the latter experiments the rate offiltration increased within ten to twenty minutes after the administrationof the drug, but this rise in filtration was more than counteracted by aconsiderable increase in the percentage of reabsorption in the tubules.

1083

ACTION OF DIURETICS

beC-4t w Oq m ON x a, I-

ts III IIIII +1++++IV

0

. wEX § o+oerNmA-.00 r'

2 . - ______________ot- oo ooM o _ oov) o

r. 4;0 0 0 0 ~0 0 ;C 0 000t-z rz - %0

0 K 7n~~~~~M %0 V-4 m %OC4 in C4 C4 w r- -tX e4

"4 0 ~~~~~~~V.- --IV4.o

g tO00t-.0o-ooo 000o

44 A4

o~~~~~~~ 00 C4 m 00 00 to tNNoto

w 00 -o mmo wo oW

tv NO 01U)UN)OU)V4 .rJU)0 r4 U)i4If ')U)ld

0

m~~~~~~U 00'U0 00 )) 4°3ou') ov zo _ooNoio

4) 44t N l)r t

0 2 0.,. - - '0-4 In so U)Ur-

- U

A X .t _ - ~~l~IZ-'O U)t.-U U

I .

IS I.

.Rr elt. U):0so.. ) L V4 C

1084

'.4a)

0.

x

v

C.)

a-)

'0

u

a)a)0

0.4

"a)

0

'4)00

0

O)4--2

*ECd

r..-

_

0.

Cd1.bi

00

O4

HENRYLENZEN SCHMITZ 1085

175

8~~~~~150

4,N4zI 4,, ffi j 't"'125

U2i, 100I ~~~G

3 X 7.85 L

U 2 \ : 50 MR E

1i /\ - @\ < < 9 25 RN 2-- UE 0 3

4 64

l L

A

0 ~~~ ~~~~~AI200 R

LIG 1. RAT 4F41OERLAFITATO FUIGEPYLNDUEI

L ~~~~~~~~~~~~~~~~~~~~~~~~~~~IU''' 175 LME Ti

250 R

/ I <125,

0 50P

FIG 1.RT2FGOERLRFLRTO5DRNUHL DIREs

The arrows indicate when euphyllin was injected. Solid line = urinevolume. Broken line-=glomerular filtrate.

This is illustrated by Figure 3 in which one of the experiments is presentedgraphically.

Salyrgan experimentsThe results obtained with salyrgan (see Table 3 and Figure 2) are in

sharp contrast to those given by euphyllin. The percentage reabsorptionin the tubules was significantly decreased in all but one instance, thedecreases ranging from 1.6 to 4.6. A definite increase in filtration, on theother hand, occurred in only four of the fourteen experiments and in onlyone instance (experiment 6) played any significant r8le in the productionof diuresis.

ACTION OF DIURETICS

Salyrgan was effective even when the control urine volume was ashigh as 3.5 cc. per minute. Rates of urine excretion as high as 5, 6.8 and9.4 cc. per minute were obtained. The response to salyrgan is less rapidthan that to euphyllin. In the majority of experiments diuresis began 15to 20 minutes after the intravenous administration of the drug. Therewere only two instances in which salyrgan failed to cause diuresis.

uRINE

V0LUME

CC

pER

MINUT

150

125

100

75

50

25

0

100

75

50

25

0

GL0MERULAR

FILTRATI0N

CC

pER

ME A<125Io N

Thearows inicaeweaygnwsijce.Sldln = uineolume

3> ~~~~~~~~75E2> ~~~~~~~~~~~~~~~~50

1 25

0 6 ii1 9

FIG. 2. RATE OF GLOMERULARFILTRATION DURING SALYRGAN DIURESISThe arrows indicate when salyrgan was injected. Solid line = urine volume.

Broken line = glomerular filtrate.

Intravenous normal saline solutionBecause many investigators have maintained both in the case of

euphyllin and in the case of salyrgan that diuresis is the result of a primary

1086

HENRYLENZEN SCHMITZ

extra-renal mobilization of salt and water the effect of normal salinesolution given intravenously was studied for purposes of comparison.The amount of saline and the rate of injection were varied considerably.See Table 4.

Per centReabsorp-tion ofwater intubules

GlomerularFiltrationin cc. perminute

UrineVolumein cc. perminute

100.0 -_ _ -L -

99869912 -98.8 -980 - - - - - -

98.0- jilt97.697.2 _ -_ _I1_

96.0 n_ _ by_]g_ W__ ____

200 _ _ _ _ _ _190180170 -

140 _ _- _ - - _

130

4.0 _< + -_z Tllo_3 1_T11_0o2.0L _

Time in minutes 10 20 30 40 50 60 70 80 90 100

FIG. 3. EFFECT OF EUPHYLLIN DURING WATERDIURESIS

The almost constant increase in rate of glomerular filtration followingthe injection of saline was outstanding in these experiments. The effectupon reabsorption varied with the amount and the rate of injection ofsaline. With the smaller amounts decreases in reabsorption wereinfrequent and seldom significant. When saline was injected continu-ously at fairly rapid rates, larger decreases in percentage reabsorptionoccurred. In the latter experiments the increases in filtration alwaysappeared first. As the injection was continued the rate of filtration

1087

ACTION OF DIURETICS

4)

a)i

.00

4U)

I ODIw mQ0 q w0% " ON00 % o ON " C*nU ..- .* @ .I.. 6 r.: 'i)r rzo X _

aR .6 t .. g 'i "iI qd4 W-

~ -4a 00~0 ,0C'fj 4to00 Cje#m0 %1 0 . C~. 0%: 0% 0 ~ C0% 00 00

.0 "

t; 0X N o~ a, _7 o7 o45 0 0ON _ ON ON

! 2 I I +++ I+II+II+

a ls 00 "4X<

J g

a M~~~0

0

@ e m O m_o in ON

p0~~~~~N tn V4 qt w W o o

.E~~~ . .

0t C t o. " 4_N m " m %m

mt~~~~~~~C4etom mtn>o

UN

tn__________4

Xig~~~NO m0 -0I1o_o O_mmma

1088

0.0b

4%.

CU

4)4

I

CU

4%,A lb

C'"I

a)._

cU

baCUC'

'0

4.)

a)

xia)

*.a).C4.0

CU

'0

_a)

a)

CU6

bo4-

0tC.C.

-6$t C. 0 NO 0 -4 In 0. 140 V-4 10 V-4 W M.O

.9 t V4 cli cli 4 4 t-i C-i "4 4 cli 14 C-i el; 4t I I I I I I I I I I + I I I

u .104I

HENRYLENZEN SCHMITZ

D4)

.0

34)

._

0u)

04

Cd4-) 6I-+0+5

U) U q

(ei 0lI

'w 6 6 6 0 £. 0 0 ) '3

0 0% 0% 0II0C1 0% 01 0% 1 0It;ChollONON ON~~~~~~.

'4 C 06t 7 a

0%0%

U)

000%

i:- 00

C% 0%ON 0 %

I0%0%ONc 0%

0%

000%

'00%0' o%

0i U 00 O I N I UII + + I+l +l + + + +

A g| Ee]EoO CA |:|||u

E~~~~~~~O o ".4 -4

44gw

'0 00 - 0 0 tt- U)

r- - -

0D a-X _____-

4)

'U° 0c'* U) el '0 U) e'i$10%>

:3 It 0°l °l 00 ' '3-I U) 0 -

0 0 0 - I- IU I °V.) 0 0

~~~~~~44~~~~~~~~~~~~~~~~~Ii4~~-J 4J 4J - -

'5 0 %.S IOU I U) U) O ) U) I OI II

1 001Ss -1 '0 0-1 U) 0 -11 4-l i 0

A1 0t 03°- C' o el C° U) el >

t) 000 "1 U) U) -

4e4 - e U 4 U U) - U U%.

0 ! . 0 .0 (O ! !0: 0 V0 V0 ~ 0- - - -

9a

0%Ilot 1u )v1 IoIn Ito)

00 vo

1089

'.oQ

.004)

m4.

I

rt

:t

*.b

.4)

4).

'4-"''

'4-0

%.)

,;o

be- la$3 O0Ir. 4i. z

=1 93 v0 0,p u

ACTION OF DIURETICS

tended to subside while reabsorption decreased. In experiment 26 therate of filtration, after an initial rise, dropped below the control periodlevel.

COMMENT

In the experiments with salyrgan, diuresis was characteristicallyassociated with a decrease in tubular reabsorption. Chrometzka andUnger (72) made the same observation. The fact that there is no re-semblance between salyrgan and intravenous normal saline solution, sofar as effect upon filtration is concerned, is opposed to the view that theresponse of the kidneys to this mercurial diuretic is secondary to anextra-renal mobilization of salt and water. The observations of Gremelsand Govaerts, referred to above, also indicate a direct action on thekidneys. Since larger doses of mercury injure and destroy the epitheliumof the renal tubules, it seems logical to assume that this decrease intubular reabsorption is due to a depressant action upon the tubule cells.

Chrometzka and Unger performed three experiments with diuretinand found no change in the rate of glomerular filtration. In the experi-ments reported in this paper, however, an increase in rate of glomerularfiltration was characteristic of euphyllin diuresis. This finding is con-sistent with the direct observation of Richards and Schmidt that caffeineincreases the number of functioning glomeruli and the number of func-tioning capillary loops in individual glomeruli. It is also in harmonywith Bieter's observation (74) that caffeine and theophyllin do notproduce diuresis in fish with aglomerular kidneys.

Since the intravenous injection of normal saline solution also increasesthe rate of glomerular filtration it is impossible to conclude from theseexperiments alone whether xanthine diuretics act primarily upon thetissues or upon the renal vessels. The fact that these diuretics areeffective in increasing the urine output of the isolated kidney is definitelyopposed to the former view. The principal objection to the latter theoryhas been the lack of correlation between xanthine diuresis and rate ofblood flow through the kidney. This objection loses its significance ifwe assume, as Verney and Winton (22) have proposed in the case ofcaffeine, that the xanthine diuretics may, under suitable circumstances,dilate the vas afferens to a greater extent than the vas efferens and thusincrease the glomerular capillary pressure, the glomerular capillary surfaceand the rate of glomerular filtration without necessarily increasing therate of blood flow through the kidney.

Changes in reabsorption following the injection of euphyllin areinconstant. The moderate decreases occurring in many experiments maywell be related to increases in the number of patent capillaries in individualglomeruli, larger amounts of fluid flowing down the corresponding tubulesmore rapidly and lessening the chances for reabsorption.

The diuretic response to salyrgan is considerably greater than that to

1090

HENRYLENZEN SCHMITZ

euphyllin. This difference is related to the relative effect of increases infiltration and decreases in reabsorption upon urine volume. Even largeincreases in filtration can not per se produce large urine volumes whereasrelatively small decreases in reabsorption can cause considerable diuresis.

Per centReabsorp-tion ofwater intubules

GlomerularFiltrationin cc. perminute

UrineVolumein cc. perminute

98 ------

97 I _ _96 _ _ __ _95--. -- _ __ v94 _ _ __93.---923_.----- _91- -- _ __

120 - ---115---. --110-- ----1051- IT _ I -100 _ x- ._ T90-- 1 - -85------80 -.-- - I -75 -70 - _ _65 1 -60

1--

2--i-I-3

Time in minutes 10 20 30 40 50 60 70 80 90 100 110 120 130

FIG. 4. EFFECTOF EUPHYLLIN DURINGCONTINUOUSINTRAVENOUSINJECTIONOF NORMALSALINE SOLUTION

Fremont-Smith and his associates (75) found that water diuresis inman was not associated with an appreciable increase in the amount ofglomerular filtration. Chrometzka and Unger (72) have made the sameobservation. In the experiments herein reported, the rates of filtrationassociated with high control urine volumes, produced by forcing largeamounts of water, were moderately higher than the rates of filtrationassociated with low control urine volumes. The average rate of filtration

1091

ACTION OF DIURETICS

during 38 periods with urine volumes below 1 cc. per minute was 54 cc.per minute, while the average rate for 10 periods with urine volumesbetween 3 and 4 cc. was 78 cc. per minute.

The amount of reabsorption, on the other hand, is considerably re-duced during.water diuresis. As -the diuresis subsides the percentagereabso-rptsinii mounts rapidly. This rise in percentage reabsorptionwould seem to b'e the sigtiificant factor. in the failure of euphyllin toincrease urine volume under these conditions (see Figure 2). Filtrationis .increased, but the rising percentage of reabsorption in the tubulesmore than counteracts the increase in rate of filtration. Presumably ifwater were administered at a constant rate so as to maintain the per-centage of reabsorption at a level, euphyllin would be capable of increasing

wNou|EvPhYllit | I I W |~~~~~~~SalyrplA l

900 2 + 6 8 10 0 2 + 6 8 1O

Urive volmne hw e per ,mellt

FIG. 5. GRAPHIC COMPARISONOF THE EFFECT OF EUPHYLLIN ANDSALYRGANUPONGLOMERULARFILTRATION AND TUBULAR REABSORPTION

After direXtc-b.

the urine -volume still further. Euphyllin is effective when the urineoutput is high as a result of the continuous injection of normal salinesolution (Figure 4). It is in fact more effective than usual under thesecircumstances, because the low percentage of reabsorption in the tubulesmakes the resulting increase in filtration more significant. Similarresults were obtained in two other experiments of this type.

These experiments are of interest to the clinician because they maylead to a better understanding of the clinical results obtained with thesedrugs. Clinically it has been found that the xanthine diuretics are chieflyof value in hastening the elimination of cardiac edema after digitalis andbed rest have improved. the circulation. With improvement in circulationin cardiac failure salt and water previously stored in the .tissue spaces arebrought to the kidneys for excretion. Under these conditions, as we haveseen experimentally, the increase in filtration produced by the purine

1092

HENRYLENZEN SCHMITZ

derivatives is more effective than usual because reabsorption is takingplace to a lesser degree than normal. In other types of edema (hepaticand renal) the xanthine diuretics are of little help. Increase in filtration,especially when only of a transient nature, is by itself of little value inaugmenting the urine output.

The mercurial diuretics, on the other hand, are effective in all threeof the above mentioned types of edema. The effectiveness of salyrganand novasurol in the case of cardiac edema is readily understandable.It is more difficult, however, to account for the removal of accumulationsof fluid resulting from portal obstruction and from depletion of the plasmaproteins. Presumably the loss of water from the plasma resulting fromthe administration of these mercurial diuretics is sufficient to secondarilyattract fluid from the tissue accumulations into the blood. With ourpresent information, however, one can do little more than speculate inthis regard. Further observations, both on the experimental animal andon patients with edema, are necessary before one can draw any definiteconclusions.

SUMMARY

Rehberg's method of calculating the amount of filtration occurringin the glomeruli and the amount of reabsorption taking place in thetubules was used to compare the diuretic action of euphyllin and salyrganin the dog.

During euphyllin diuresis the calculated amount of glomerular filtra-tion is consistently increased while tubular reabsorption shows no constantchange.

Salyrgan diuresis is characterized by a considerable decrease in thepercentage of fluid reabsorbed in the tubules. The amount of filtrationis seldom increased significantly.

The intravenous injection of normal saline solution characteristicallyincreases the rate of glomerular filtration. The effect upon reabsorptionvaries with the amount of saline and the rate of injection.

The mechanisms by which mercurial and xanthine diuretics producediuresis are discussed in the light of these findings and of the evidenceavailable in the literature.

BIBLIOGRAPHY

1. Von Schroeder, W., Arch. f. exper. Path. u. Pharmakol., 1887, xxii, 39.Ueber die Wirkung des Coffeins als Diureticum.

2. Von Schroeder, W., Arch. f. exper. Path. u. Pharmakol., 1888, xxiv, 85.Ueber die diuretische Wirkung des Coffeins und der zu derselben Gruppegehorenden Substanzen.

3. Loewi, O., Fletcher, W. M., and Henderson, V. E., Arch. f. exper. Path. u.Pharmakol., 1905, liii, 15. Untersuchungen zur Physiologie und Phar-makologie der Nierenfunction. III. Mitteilung: Yber den Mechanismusder Coffein-diurese.

1093

ACTION OF DIURETICS

4. Phillips, C. D. F., and Bradford, J. R., J. Physiol., 1887, viii, 117. On theAction of Certain Drugs on the Circulation and Secretion of the Kidney.

5. Gottlieb, R., and Magnus, R., Arch. f. exper. Path. u. Pharmakol., 1901,xlv, 223. Ueber Diurese. IV. Mitteilung: Ueber die Beziehungen derNierencirculation zur Diurese.

6. Brings, L., and Molitor, H., Arch. f. exper. Path. u. Pharmakol., 1931, clix,710. UYber die Beziehungen zwischen onkometrisch verzeichneten Gros-senanderungen der Niere und Diurese.

7. Cushny, A. R., The Secretion of the Urine. Longmans, Green & Co. Ltd.,London, 1926, 2nd ed., page 152.

8. Cushny, A. R., and Lambie, C. G., J. Physiol., 1921, lv, 276. The Actionof Diuretics.

9. Schmidt, Erich, Arch. f. exper. Path. u. Pharmakol., 1924, ci, 66. Tier-experimentelle Untersuchungen uber die Beeinflussung der Nierenfunk-tion durch intraven6s einverleibtes Sublimat und Neosalvarsan unterbesonderer Berticksichtigung des sogenannten Linserschen Gemisches(Neosalvarsan + Sublimat).

10. Ozaki, Masamichi, Arch. f. exper. Path. u. Pharmakol., 1927, cxxiii, 305.Pharmakologie der Nierengefasse.

11. Schmidt, Robert, Arch. f. exper. Path. u. Parmakol., 1922, xcv, 267.Ober Diureseversuche an uberlebenden Froschnieren.

12. Richards, A. N., and Plant, 0. H., J. Pharmacol and Exper. Therap., 1915,vii, 485. Urine Formation by the Perfused Kidney: Preliminary Experi-ments on the Action of Caffeine.

13. Gremels, H., Arch. f. exper. Path. u. Pharmakol., 1928, cxxx, 61. Ober dieWirkung einiger Diuretika am Starlingschen Herz-Lungen-Nieren-praparat.

14. Gremels, H., Klin. Wchnschr., 1928, vii, 1791. Zur Pharmakologie derDiurese.

15. Miwa, M., and Tamura, K., Mitt. d. Med. Fak. d. k. Univ. zu Tokyo, 1920,xxiii, 349. Beitrage zur Physiologie und Pharmakologie der Nierenfunk-tion. II. Uber das Wesen der Coffeindiurese und den Einfluss derSalicylsaure auf die Niere.

16. Hartwich, Adolf, Arch. f. exper. Path. u. Parmakol., 1926, cxi, 206. Einflusspharmakologisch wirksamer Substanzen auf die isolierte Froschniere.II. Mitteilung: Diuretika und andere Substanzen.

17. Dreyer, N. B., and Verney, E. B., J. Physiol., 1923, lvii, 451. The RelativeImportance of the Factors Concerned in the Formation of the Urine.

18. Richards, A. N., and Schmidt, C. F., Am. J. Physiol., 1924, lxxi, 178.A Description of the Glomerular Circulation in the Frogs Kidney andObservations Concerning the Action of Adrenalin and Various OtherSubstances upon It.

19. Richards, A. N., and Plant, 0. H., Am. J. Physiol., 1922, lix, 184. UrineFormation in the Perfused Kidney. The Influence of Adrenalin on theVolume of the Perfused Kidney.

20. Richards, A. N., and Plant, 0. H., Am. J. Physiol., 1922, lix, 191. TheAction of Minute Doses of Adrenalin and Pituitrin on the Kidney.

21. Mendenhall, W. L., Taylor, E. M., and Richards, A. N., Am. J. Physiol.,1924, lxxi, 174. TheActionof MinuteAmountsof BariumChloride uponthe Kidney.

22. Verney, E. B., and Winton, F. R., J. Physiol., 1930, lxix, 153. The Actionof Caffeine on the Isolated Kidney of the Dog.

23. Barcroft, J., and Straub, H., J. Physiol., 1910, xli, 145. The Secretion ofUrine.

1094

HENRYLENZEN SCHMITZ

24. Gremels, H., Arch. f. exper. Path. u. Pharmakol., 1929, cxl, 205. Uber denEinfluss von Diureticis auf den Sauerstoffverbrauch am StarlingschenNierenpraparat.

25. W'ohlenberg, Willi, Arch. f. d. ges. Physiol., 1927, ccxviii, 448. Uber dieHarnbildung in der Froschniere. XIII. Mitteilung: Untersuchungenuber den Mechanismus der Purinkbrperdiurese.

26. Barcroft, Joseph, Ergebn. d. Physiol., 1908, vii, 744. Zur Lehre vomBlutgaswechsel in den verschiedenen Organen. Die Nieren.

27. Hayman, J. M., Jr., and Schmidt, C. F., Am. J. Physiol., 1928, lxxxiii,502. The Gaseous Metabolism of the Dog's Kidney.

28. \Iasuda, T., Biochem. Ztschr., 1926, clxxv, 8. Uber dieW7irkung diuretischerGifte auf die cyanvergiftete Froschniere.

29. Sobieranski, XV., Arch. f. d. ges. Physiol., 1903, xcviii, 135. Wkeitere Beitragezur Nierenfunction und Wirkungsweise der Diuretica. Ueber dieVeranderung der Nierenepithelien unter dem Einfluss verschiedenerDiuretica.

30. Tashiro, K., and Abe, H., Tohoku J. Exper. Med., 1922, iii, 142. The De-pendence of the Nature of Caffeine Diuresis upon the Dose Used. I.Renal Oxygen Consumption and Blood Flow during Caffeine Diuresis.

31. Teploff, I., Ztschr. f. d. ges. exper. Med., 1929, lxix, 159. Die Purindiureseim Lichte der vitalen Carminfarbung.

32. Bruhl, H., Biochem. Ztschr., 1929, ccxii, 291. Untersuchungen zur Mlem-bran- und Eiweiszwirkung des Coffeins.

33. Veil, XV. H., and Spiro, P., Miinchen med. WVchnschr., 1918, lxv, 1119.Ueber das WVesen der Theocinwirkung.

34. Ellinger, A., Heymann, P., and Klein, G., Arch. f. exper. Path. undPharmakol., 1921, xci, 1. Die treibenden Krafte fur den Fluissigkeits-strom im Organismus, Quellungsdruck der Eiweissk6rper und Diurese.Zur W'irkungsweise des Coffeins als Diuretikum.

35. Fllinger, A., and Neuschlosz, S. M., Biochem. Ztschr., 1922, cxxvii, 241.Vergleichende Untersuchungen uiber Viscositat und Ultrafiltrations-geschwindigkeit von Serum.

36. Faludi, Franz, Ztschr. f. d. ges. exper. Med., 1928, lxii, 242. Uber dieCoffeindiurese.

37. Meyer, Paul, Ztschr. f. klin. Med., 1931, cxvi, 687. Untersuchungen uiberden kolloidosmotischen Druck des Blutes. III. Die Euphyllindiurese.

38. Curtis, G. Ml., Biochem. Ztschr., 1925, clxiii, 109. Beitrage zur Physiologieder Driusen. Die Wirkungsweise der spezifischen Diuretica nebstBeitragen zur Lehre vonder Harnabsonderung.

39. Curtis, G. M., Biochem. Ztschr., 1927, clxxxvi, 95. Fortgesetzte Unter-suchungen uber die Wirkungsweise der spezifischen Diuretica. DieBlockierung der normalen Reaktion durch die intraperitoneale Injektionvon destilliertem WAasser.

40. Curtis, G. M., and Shambaugh, N. F., Biochem. Ztschr., 1927, clxxxvi, 112.Fortgesetzte Untersuchungen uiber die WVirkungsweise der spezifischenDiuretica. Die Blockierung der normalen Reaktion bei Kaninchen mitentnervten Nieren.

41. Curtis, G. M., Klin. X'chnschr., 1925, iv, 824. Die Wirkungsweise derspezifischen Diuretica.

42. Hartwich, Adolf, Biochem. Ztschr., 1926, clxvii, 329, Uber die Beziehungendes Blutkochsalzspiegels zur Diurese.

43. Riesen, WVerner, Biochem. Ztschr., 1930, ccxxvi, 441. Der Elektrolytaus-tausch zwischen Gewebe und Blut unter dem Einflusse der spezifischenDiuretica, ein Beitrag zur Lehre von der Diurese.

72

1095

ACTION OF DIURETICS

44. Nakao, H., Biochem. Ztschr., 1926, clxxiii, 41. Vergleich der Wirkung-sweise des spezifischen Diuretika bei normalen und dyspnoischen Tieren.

45. Nakao, H., Biochem. Ztschr., 1926, clxxviii, 342. Fortgesetzte Untersuch-ungen zur Lehre von der Harnabsonderung. Die Wirkung der spezi-fischen Diuretica unter dem Einflusse des vegetativen Nervensystems.

46. Raulston, B. O., Biochem. Ztschr., 1927, clxxxiv, 31. Fortgesetzte Unter-suchungen zur Lehre von der Harnabsonderung. Die Wirkungen derspezifischen Diuretica im allergischen Zustand.

47. Buichler, H. W., Biochem. Ztschr., 1931, ccxxxiv, 441. FortgesetzteUntersuchungen fiber die Wirkungsweise der Diuretica.

48. Molitor, H., and Pick, E. P., Biochem. Ztschr., 1927, clxxxvi, 130. UYberzentrale Regulation des Wasserwechsels. IV. Die Aufhebung derdiuretischen Coffein- und Theobrominwirkung durch Zwischenhirn-narkose.

49. Saxl, P., and Heilig, R., Wien. klin. Wchnschr., 1920, xxxiii, 943. Ueber diediuretische Wirkung von Novasurol- und anderen Quecksilberinjek-tionen.

50. Crawford, J. H., and McIntosh, J. F., J. Clin. Invest., 1925, i, 333, Observa-tions on the Use of Novasurol in Edema due to Heart Failure.

51. Keith, N. M., and Whelan, M., J. Clin. Invest., 1926, iii, 149. A Study ofthe Action of Ammonium Chlorid and Organic Mercury Compounds.

52. Melville, K. I., and Stehle, R. L., J. Pharmacol. and exper. Therap., 1928,xxxiv, 209. Mercury Diuresis.

53. Moller, Knud, O., Arch. f. exper. Path. und Pharmakol., 1930, cxlviii, 56.Experimentelle Untersuchungen fiber die Pharmakologie des Salyrgans.I. Mitteilung. Untersuchungen fiber die Salyrgandiurese bei Kaninchen.

54. Nonnenbruch, W., Munchen med. Wchnschr., 1921, lxviii, 1282. Ueberdie Wirkung des Novasurols auf Blut und Diurese.

55. Saxl, P., and Heilig, R., Ztschr. f. d. ges. exper. Med., 1923, xxxviii, 94.Uber die Novasuroldiurese.

56. Noguchi, Inosuke, Arch. f. exper. Path. u. Pharmakol., 1926, cxi, 295.Experimentelle Beitrage zur Kenntnis der Novasurolwirkung.

57. Bohn, Hans, Ztschr. f. d. ges. exper. Med., 1923, xxxi, 303. ExperimentelleStudien fiber die diuretische Wirkung des Novasurols.

58. Bohn, Hans, Deutsches Arch. f. klin. Med., 1923, cxliii, 225. FortgesetzteStudien fiber Novasurol, seine Wirkung bei verschiedenen Lebensalternund bei Diabetikern, sowie sein etwaiger Einfluss auf Ionenverschieb-ungen im Organismus.

59. Serby, A. M., Arch. Int. Med., 1926, xxxviii, 374. The Pharmacology andTherapeutics of Novasurol.

60. Mtihling, A., Munchen med. Wchnschr., 1921, lxviii, 1447. Studie fiber diediuretische Wirkungsweise von Quecksilber. Ausgefuihrt mit demorganischen Quecksilberpraparat Novasurol.

61. Bleyer, L., Klin. Wchnschr., 1922, i, 1940. Erfahrungen fiber die Nova-suroldiurese.

62. Feher, Stephan, Wien. klin. Wchnschr., 1929, xlii, 964. Salyrgandiureseund zirkulierende Blutmenge.

63. Tezner, Otto, Med. Klin., 1923, xix, 788. Zum Mechanismus der Nova-surolwirkung.

64. Recht, Georg, Wien. klin. Wchnschr., 1926, xxxix, 1046. Zur gewebsdiuret-ischen Wirkung des Salyrgans.

65. Brunn, F., Munchen med. Wchnschr., 1921, lxviii, 1554. Zur Wirkung desNovasurols als Diuretikum.

1096

HENRYLENZEN SCHMITZ

66. Meyer, Paul, Ztschr. f. klin. Med., 1931, cxvi, 174. Untersuchungen uiberden kolloidosmotischen Druck des Bluts. II. Die Salyrgandiurese.

67. Fodor, Emmerich, Med. Klin., 1923, xix, 684. UJber das Indikationsgebietdes Novasurols als Diuretikum.

68. Govaerts, Paul, Compt. rend. Soc. de biol., 1928, xcix, 647. OrigineRenale ou Tissulaire de la DiurPse par un Compose mercuriel organique.

69. Schloss, Anneleise, Arch. f. exper. Path. u. Pharmakol., 1930, clii, 27.Salyrgandiurese und Ni erendurchblutung.

70. Kulcke, E., Klin. Wchnschr., 1922, i, 622. Novasurol als Diureticum.71. Rehberg, P. B., Biochem. J., 1926, xx, 447. Studies on Kidney Function.

I. The Rate of Filtration and Reabsorption in the Human Kidney.72. Chrometzka, F., and Unger, K., Ztschr. f. d. ges. exper. Med., 1931,

lxxx, 261. Untersuchungen uber die Grosse des Glomerulusfiltrats unterdem Einfluss von Diureticis und Hormonen.

73. Folin, Otto, J. Biol. Chem., 1914, xvii, 475. On the Determination ofCreatinine and Creatine in Blood, Milk and Tissue.

74. Bieter, Raymond, N., J. Pharmacol. and Exper. Therap., 1931, xliii, 399.The Action of some Diuretics upon the Aglomerular Kidney.

75. Fremont-Smith, F., Fremont-Smith, M., Dailey, M. E., Solomon, P.,Stetten, De W., jr., and Carroll, M. P., J. Clin. Invest., 1930, ix, 7.Studies in Edema. I. The Mechanism of Water Diuresis in Man.

76. Ekehorn, G., Acta med. Scandinav., Supp., 1931, xxxvi, 1-717, On thePrincipals of Renal Function.

1097