DIURESIS DURING FLUID INFUSION , BUFFER NERVE ANDSPINAL INFLUENCES ON IT

T.P. SURESH AND K.N. SHARMA·

Department of Physiology. Veten'nary College.UnivefSllY of Agnculrural Sciences. Hebbal. 8angalore·560 024

and

Depanmem of Physiology and Medical Elecrronics.Sl John"s Medical College. Bangalore·560 034

s.-wy: The r.......d a.1I"ul.tNe volume of diu'esis Wtn mNSUrecl Mq\WIllelty for Mdl lrtet..RWnl.1 11"""01'1 dose of 5 ""Ikg bocfy _gl'lt till • 100 mllkg or mote doN w.. reached. Norrmlsaline (N5). F!ulg_·lot;kl (Al) and tef>_ coconut VQte!" (TCW) __ iIlfuMd in ItlrM groups IItd> ",t

~dehyde IPlO).•nd dUor.toM Ind Ule1twJe (e & U) _lheUMd~ The I&ow Infusionfit. of about 0.5 m/lktJlmm __, used "The RlmfulllOll ....... t~.~ In v-oolQfnl.Sold end/Of c.lfObd."UI (C$) CS-V'l~ dog. Ind spinal dogs ....,th 01 Wllhout '"lad vag'.

During In. NS .nd RL ltlluSion schedules in PLD ananthebMd <IogI Ofoduced much I... urinethan C & U group-. The orOet of minimum 10 ~ximum diutllbC..n.cc caus.ed by 1,,"- fluids "'....Rl.NS Ind lCW In PLO groups In<! NS. lew.nd RL in C & U group$. The Itudy Inc\latu that the~ of a"...that••nd thl eompos.ihon of infusion fluid det¥n'IlM$ Ih. rilll ollnlusion induceel diurlSb.PLD 'l\M,hsa. hal ."ddi...retlc effect. wtlich IS not overcome byy~. In C & U anaestheUseddog5 1M YIIgototnY and CS denervauon performed M1Iar.lely grQlty InaNMO 1M! IIle 01 m'uaooninduced diufHlI but lhe du,.wl largefy decreased when comblnel:l IUfQWY _ performed. ThedlUfftiI in ICllflal dogs Wit vety low. though il'l the vagototl'llwd-:wmal dogs. the 'ate 01 d,u""s WISmore than In the ICllnill dogs.

Ka, _da: lluld infusion

spln,l cord

diuresis

lender coconut Wllllf'

INTRODUCTION

buff. n....anaeslhellMCI dogs

Cardiovascular changes during intravenous fluid infusion have beon well documented(18.19.31.32). Studies on diuresis during fluid infusion and the possible mechanism ofsuch infusion induced diuresis have also been reported (14.19.31). However. the methodsL'sed in the above studies had no relevance to clinical practice regarding the rate, volumeand type of the infusion fluid used as also the effects of anaesthesias, To fill up thislacuna, the effect of normal saline (NS). Ringer·Locke solution (RL) and tender coconutwater (TCW) ~29,30) infusion on the rate and volume of diuresis was studied in paraldehyde(PLD), and chloralose and urethane (C & U) anaesthetised dogs receiving upto 100 mIlky

""'_I'll acldllt5S o.par\ll'lont 01 Physiology. UnivelSity College 01 MedIcal SciellCis. Ring Ro.a. New Delh!·1100HI.

158 Su'esh .nd Shlfm. July·September 1979Inet J. Phyllol Phlrmac.

body weight or more of the above fluids at a slow rate. Many workers (8.13) have sugges­ted that buffer nerves may playa role in diuretic response in dogs. To evaluate the possiblerole of vagi. carotid SInus (CS) nerves and spinal cord in Infusion induced diuresis. theRl infusion was repeated in vagotomised and/or CS denervated and spinal dogs.

MATERIALS AND METHODS

Seventy-eight mongrel dogs (7-20 kg) of both sexes in 12 groups as describedin detail by Swash (32) Wefe used. Dogs were kept on ad libitum food and water sche·dules before use. The dogs were offered water before anaesthelic induction. PlDwas in\Kted Into thigh muscles at 2.2 ml/kg body weight. C & U anaesthesia was gIVenone haUl after premedlcanon With morphine hydrochloride (1 mgikg body weight). Thedogs were anaesthetised to Plane 3 of surgical anaesthe~a (7) and maintained at thatlevel by infUSing 1 to 2 mlof anaesthetIC mIXture whenever the blrnking reflex reappeared,A total of 0068 to 0.102 g chloralose and 1.02 to 1.52 9 of urethane were used per kgbody W8lght in various dogs including supplementary doses.

The basal preparations In intact groups (Gl to G6) Included intratracheal intubation.femoral artetV and vetn can"tulalion. Unnary bladder was cathetensed ttvough urethraWith a lubllC8ted fleXible polyethylene tube (2 mm diameter for male and 5 mm diameterfor female). The expenrTlftntal surgetV groups (G7 to G12) in addition underwent surgerie!..as descrIbed In detail by Suresh (32). AoprojYiate checks were conducted to find outthe efficacy of the surgenes Only young dogs of 1·2 years of age were used for sPinaluansectlons as the prehmlnary studIes indicated that aged dogs were susceplIble to spinal

shock.

The urinary bladder was emptied before the start of the Infus,on. Urine dropswere recorded uSIng drop recorder (E & M Instruments. Houston, Texas. USA. 92-100-70)or a recorder deSigned and fabricated in our laboratory. The urine collected during eachincremental infusion dose (5 ml/kg body weight) was measured till 100 ml/kg stage ormore was reached. The bladder was palpated regularly to ensure that no urine was retained.The cumulative urine volume was calculated by adding together the successive urinevolumes produced at each infusion stage. Fresh NS. RL (pH 7.4) and TCW were infusedat room temperature via femornl vein al a constant rate (0.5 to 0.9 ml/kg/min) as indicatedin Table I of Suresh (32). Samples of TCW infused were analysed for pH and electrolytes.

Analvsis .' The regression curves were fitted to mean rate and mean cumulativeurine volume produced al each infusion stage by using orthogonal polynomials. Theintergroup comparison of net rate and net cumulative urine volume (net '"" mean takenacross the entire infusion schedule) were done by Bartlett's test as descnbed in Snedecorand Cochran (28).

•

V",t...".. 23 'OUlItJiI during Fluid lnlulion 15'N"_ 3

RESULTS

The rate and cumulative volume of urine produced at selected infusion stages inInlact and experimental surgery groups are presented in Tables I. and II. Table III givesnet rat" and volume of urine produced. A-values (multiple correlation coefficient) of finedregression curves and intergroup comparison of net rate and volume of diureSIS. Figs. 1.

2 end 3 give the regressIon curves of rate and volume of diuresis_ Generalty. PtD groups

TABLE I : RII. of U'tr'le formlibOn (m/') belWeen two .1ICCeh1Yl intullon .U>gn.

,"'- "- (mJlkfI -. _'JG.

f.~ '0 20 30 '0 '0 00 70 80 .0 '00

G, M o , 2.7 3 8 8 0 7.8 2 8 2 • 1 8 30 2.2

• , 0 3 • •• 11.9 133 •• 3.1 I • 3 0 L3

G2 M 1 0 o , 08 o • ... 2.' 1.' 2 3 120 3 •

• ,. o 8 o , 0.' 1.1 3 , 2 3 2.2 11 8 2 2

G3 M• 0

70 7 8 8.8 13' "8 1<0 13.0 173 13.0

• 3 7 •• 2 2 ,., 8 8 ,3< .., ., 9 , 9 8

G' M 1 , 3 8 8.8 10.3 1<0 10.0 '02 .. 10 , 12'

• 1 2 2.' , I 13' 17.7 100 12.5 3.8 13' 10 ,

G' M• 0

33 , 8 172 128 223 158 138 170 17.2

• 3 2 1.8 8 8 12.0 8 8 137 10 2 8 8 11 0 9.1

08 M 2.0 ., 130 10 , 1<8 128 11 0 , , 83 128

• • 0, , 11 • , 1 150 11 2 10 2 7.0 ., ..,

G7 M 1 8 I 1 1 8 I • 2 , 3 3 .., , 0 ,.. 83- 3< , I 1., 1.3 2 •• 0

,., ,.,• ,., ..G8 "

, , 7 0 123 " 2 187 258 22' 25.1 22' "3

• .., .. , 2 22.0 I< , 228 "8 19.e 15.1 18 ,

<9 M '.0 8 8 13.0 24.8 27.0 170" 0

17.2 22.8 31 ,

• '.0 10.0 12.6 ,,, 20 8 11.4 17.2 18.8 1<0 21.5

G'O M , 2 3.' , .0 8.8 8.0 8.2 '.6 8 0 8.' 10.2

• 1.8 3 1 '.2 , , 7 8 8 3 '.2 '.8 11.9 , 8

GI1 M o , 2.2 0.' 3 , 1.2 2.8 '.0 '.0 2. , 1.2

• o , 1.7 1.0 ,., 1.2 3. , 6.2 6. , '.3 2 .•

G12 M o 0 00 o 0 2 7 • 2 6 2 10.0 '.3 6.3 12 ,- 0.0 o 0 o 0 • 8 •• 11 • " 8 ,• 3 , , 8

G. No .. Group numbel"; M - G10up me.n; • Slllnoard devl.tlon.FIJI Ot/'" IIbbrevill!ionl M1l fig. 1.

160 Sur,V1 .nd Shlll'm. July-September 1979tnd J. PtlVSlol, Ph8l'/mc.

(Gl and G2) produced less urine than C & U groups (G4. G5 and G6) except duringleW infusion (G3. Table I). R·value of the fitted regression curves was high Indicatinggood fit (Table Ill). Indlv,dual varialion in diuretic response was high in all the groups.

TABLE II ; Cumul'l.l\l' urine pl'oduction (mI) .t varlOU. 'I~ 01 intuslon.

InflJsioIf suga (mJlJcg body _ghf)

G. BU UPNQ DES 10 20 30 .. 50 60 70 80 90 100

G' .. 1 • 14 30 .. " " 61 " 7,

• 2 .0 15 .. .. 75 80 81 " ••G2 .. 70 2 3 , , • 13 16 20 " S3

• 115 3 • , , • • 12 11 30 34

.3 .. 33 ," " '7 70 100 '30 '" .80 24'

• 33 , , • 17 22 31 " 35 S2 34

G4 .. 82 3 10 23 " .. " 113 132 '"~ 173• SO 2 3 10 31 68 83 117 .41 183 182

•• .. '0' • " " " 82 '19 162 183 217 m• .. • • 16 34 .. 80 77 86 112 130

6. .. sa 3 10 32 " 82 .07 137 ". 178 19.

• 83 , 13 28 " 62 .. .. '02 11. 122

• 7 .. .. 3 3 7 11 " 22 30 41 " 71 ..• 68 • • 7 • • 11 17 " 39 S2 63

•• ., 70 18 13 " .. 61 118 187 213 261 304 3S2

• 92 14 12 20 " 61 86 130 186 197 228 24.

G. ., 78 3S 11 " " .. ,.. '90 228 283 302 m• 62 30 • 18 36 sa 85 100 .30 '50 171 190

6'0.,

" 7 3 • 17 29 .. 62 73 " 10. 130• " 3 3 7 13 22 34 " 49 " " 97

611 M 58 11 , • 17 " 28 39 .. 65 63

• 65 12 2 , , • • " " 32 33

612 M 39 • 0 0 2 • 18 29 49 '0 70 91

• 32 • 0 0 2 • • " 33 " 40 '0

G.No. - Group "Umber: - No< Ie<:orded: M - Gr()l,lp molln;

• _ Stlnd.rd riev"llon; 8U _Volume of urine in bladder when hllldd<.1r Wilt emj:u,oo:

UP DES _ TOI.1 unn. production dunng eltpet'mlental !UfOerv.

tor ollter .bbf.VI.UOnt. '" hg. 1.

Dlur..i, during Fluid Infullon 161Volume 23Number 3

Intact groups

In PLD groups. NS. RL and TCW infusion (Gl. G2 and G3) caused 3.6. 2.7 and10.4 ml net urine flow rale and 40.4. 16.8 and 90.8 ml net cumulative urine volumes. res·pectivelv. Among the three infused. the TCW caused highest diuresis and RL theleast. Individual variation was large during NS infusion but small during RL and TCWinfusion. The net rate of diuresis duri g NS and RL infusion was similar to the rates seenin spinal dogs (G11 and G12. Table III).

NS and RL Infusion to C & U groups (G4 and G5) caused dIstinctly larger diuresIsthan in PLD groups (Table III). Therr net flow rate and net cumulatIVe urine volumewere 8.7. 12.7 and 76.8. 104 9 mI. respectively. However. TCW infuSion (GG) causedsame diuresis as In PLO group (G3. Table III). In contrast to PLD group. the RL causedhighest and the NS least diuresis. The rate of diureSIS showed a tendency to decrease in

TABLE III • Di....elK;~ 10 mfu$ion schedule.

IflUC. groups E~tM_~ lJI'OlIPS

G, G1 G3 G< GS G' G7 G6 G' G,O G" G71

(",. 1 7 10 • • 7 12.1 go 3 , 17' 17. ., ,, ,.

(') o 63" o 61" 090 085 0.88 0 83 o 95 0 94 073 079 070 077

(-) '0 • ". 90. 16 8 104 9 90 8 321 149 0 158 2 53' 28. 29.5

(iv) 088 088 099 099 099099 o 99 0 99 099 099 099 088

uc G Gil G' G7 GI G12 G'O G' G8 G' G' G. G'M ,, , 7 , ,

" ,.. ,., 87 ,., 10,4 12 7 17. 178t,)

Uc G G' Gil G12 G7 GI G,O G' G' G8 G' G8 G'M ", '88 29' 32' '0 4 53' 168908 90. 104 • 149 0 158 2

(i) Nit I,lrine flow. mflnch Infusion stlge.(ii) R vllull of thl rlorluion curve rlpreSlnting t8l8 of urine formation during infusion sChedule.

"Significant at f><('l.05. other, et P<O,Ol.(iii) Net cl,lmulativi urine volume (ml) produced during entire infusion 'chedule.(Iv) R vah,lll of the regrlulon curve representing the cumulative volume of ullne procrucod during Infusion schedule.

"Significant at P<O.05. others P<O.Ol.(vJ Intergroup compllrbon of ullne volume: (a) values have been arrllngld In ascending ordlr. (b) lIalues connecled

by the ume line are similar (P>O,05).

G _ Group. M _ Nil volume during Ule entire infusion ,chedule.

UR _ Nil urlnl flow (m/). ue _ Net cumulative utine voluml (mI).

Fat othlr obbfeVl.tioni. sel Fig. 1.

162 Suresh and Sharma July·September 1979Ind. J. Physiol. Pharmac.

later half of the infusion schedule during NS and TCW infusion but showed a platc:au

during RL infusion (Fig. 1. G4. G5 and G6).

Experimental surgery groups :

In vagotomised dogs under PLD (G7). RL infusion did not cause any diuresis intwo dogs and they were not included for calcu ation. In the remaining seven dogs the

G5

G8

G9

G3

•

3

6

9

o 20 40 60Infusion stQg~s

12

15

21

18

m(

24

Fig. 1 Regression lines of rate of diuresis (ml per infusion stllge) during 0 to 100 ml stages of infu~ion

schedule. G1 to G3 and G4 to G6 are intact PLO and C & U anaesthetised dogs r ceivingNS. RL and TCW infusion respectively; G7 to Gl;J experimental surgery group re eiving RLinfusion; G7 and G8 - vagotomised dogs uLder PLD and C U anaesthesia. G9. Gl0. Gl1and G12 CS denervated. vagOlomised·CS denervated. 5 In I and vagolomised spinal dogs.respectively.

Volume 23 Diuresis during Fluid Infusion 163Number 3

net urine flow rate and net cumulative urine volume were 3.5 ml and 32.1 ml respectivelvwhich was slightly more than the intact dogs (G2) but was similar to vagotomised spinaldogs (G12. TobIe III). Vagotomy in C & U groups (G8) in contrast largely increased thediuretic response and caused second highest diuresis among the 12 infusion schedulesstudies. The urine flow rate and net cumulative urine volume were 17.5 and 149.0 mlrespectively which was very much higher than the intact group (G5).

G5GJ

240

210 G6

-]180 G4~

E.=! 1500>

~ 120'-

:::>

90G1,G2

Infusion stag~s

t:ig.2 : Cumulative volume of urine produced (m/) during 0 to 100 ml stages ofinfusion schedule in intact dogs. See Fig. 1 for other abbreviations.

~64 Suresh and harma July·September 1979Ind. J. Physio/. PharmaC'.

CS dene~vation atone (G9) increased the diuretic response to RL infusion andcaused the highest net urine flow rate of 17.6 ml end net cumulative urine volume of 158.2mI. The urine flow rate decreased after 70 ml infusion stage (Fig. 1). Individual variationwas less in this group. CS denervation along with vagotomy (G10) decreased the diuretic.response to RL infusion and caused a net urin.e flow rate of 6.5 mL

400~

360t:

320.: p'

280

-E240-~E.2 200o>

~ 160~

::J

120

80

40

oInfusion stages

Fig. 3: Cumulative volume of urine produced (m/) during 0 to 100 ml stages of infusion schedulein experimental surgery group of dogs. See Fig. 1 for other abbreviations.

volu",,'! 23Numb r 3

Diuresis d',lrint:) lUI J Infusion 165

Spinal transection either alone (G11) or along with vagotomy ( 12) decreasedthe diuretic response to RL infusion. Two dogs died due to spinal shock and five othersdied dunng various stages of Infusion. These were excluded from analysis The net urineflow rate and net cumulative urine volume were 2.3 and 3 8. and 26.6 and 29 5 mI. respec­tively which is very much lower than 12.7 and 104.9 ml seen in intact dogs (G5. Table III).Here the diuresis was similar to intact PLD groups (G1 and G2). Vago omlsed spinaldogs (G12) produced more urine than the spinal dogs (G11).

DISCUSSIO

From the Tables I and III. it is clear that PLD groups (G1. G2. G3 and G7) producedless urine han C & U groups. The net urine flow rate and net urine vo ume (Table III)during he S. RL and TCW infusions 0 PLD and C & U groups indica e hat compositionof Infusion fluid can Influence the extent of diuresis. This is in con ras to he same typeof renal response repor ed by Papper et al. (18) and Raisz (19) for variOUS tYpes 0 flUidsinfused. In C & U groups (G4 and G5) though the Sand RL were IOfused a he samera e. he RL caused significan Iy more diuresis. a finding which does no support he reportof Jagger el al. (6) a the ra e of infusion is an importan determinan of Infus!on Induceddiuresis bu supports the above conclusion on the role of the composition of Infused Iuids.Tables I and III ur her show that PLD groups (G1 and G2) hough received IOfuslon atf ter rate than C & U groups (G4 and G5) pr~duced less urine and suggests tha anaestheticagents also determine the extent of diuresis. The mean urine flow rate (observed ratedlllJded by 10 0 express as ml/min at 50 ml/kg infusion stage in intact groups approxi­mately 500 ml total dose) was very much less than the rate of 5.2 ml/min at 60 min after500 ml saline infusion reported by Levinsky and Lalone (14).

Low rate of diuresis In PLD group (G1. G2 and G7) than 10 C & U group (Table I)indicates that the PLO suppresses the diuretic response. Vagotomy does not abolisht. antidiuretiC effect of PLD (G7. Table II) indicating that this effect is not mediatedthrough vagi. Cause of this antidiuretic effect of PLD is not clear from the available Ii e­rature. StImulation of left atrial receptors by distension causes tachycardia and diuresisduring saline infusion and this is abolished by vagotomy (8-13). PLD depresses thecholinergic transmission (17', leading to tachycardia (31). Suresh (31) has failed to observepost vagotomy tachycardia in PLD anaesthetised dogs. These evidences indicate thatthe depression of diuresis in PLD group is not due to vagolytic activitY of PLD occurringat the peripheral nerve ending. but probably due to a central effect. This conclusionrequires further v Itdation.

The diuresis during TCW infusion was high in both PLD and C & U groups (G3and G6). In PLO group. TCW caused significantly more diuresis than NS or RL Excretionof on y 198 and 244 ml urine by PLD and C & U groups during 100 ml/kg bedy weight

166 Suresh end Sherme JlJly·SoptomlW 1919lnd J. PhYllol. PhI/mac.

leW infusion dose indicates that TeW is well retained in the body as suggested by Sweshand Hegde (30). Comparison of diuresis during NS. Al and TCW infusion in C & Ugroups (Table I) suggest that the retainability of TeW in these dogs was higher than Albut tess than NS.

In PlO group. the TCW caused significantly more diuresis than NS and Al indicatingthat the TeW causes diuresis by a mechanism other than mere volume expansion. Fromthe literature available (3.29.31). it would be seen that much of the osmolarity of the lCWis contributed by a high concentration of reducing sugars resembling hydration flUids usedin clinical practice. Hence. after lCW infusion the reducing sugars get metabolised fast.decreasing the TCW osmolarity which may in turn reduce plasma osmolarity causing incre­ased urine flow. thiS suggestion may need further validation for confirmation. Surpri­singly this increased diuretic effect of lCW in PlO group is not seen to C & U group whereAL produced maximal diureSIS. Thus. the explanation put forward for PlD group Willnot fit. Selk.urt (21) reported that acidosis increased renal vascular resistance. Suresh(31) has reported increased peripheral blood flow in G3 and a fall In G6 showing theeVidence of vasoconstriction in G6. These facts suggest that the osmochlutary effect ofTCW Infusion was probably counteracted by the vasoconstriction resultmg from aCidosIScaused by TCW infusion (pH 5.1 ±O.2. Suresh. 31). ChlOlalose increases the chemore·ceptor sensitivity and depresses the baroreceptor sensilivity (15.16) which may furtherincrease the acidosIs induced vasoconstrictlon in G6.

Experimentsl surgery groups:

Vagotomy In PlO group (G7) had no effect on Al induced diuresis but largelyincreased the diureSIS in C & U group (Ga. Table II). This failure of vagotomy to increasethe diuresis In PlO group indicates that the antldiuretlC effect of PlD is not mecllated byvagal pathways,

Vagotomy (G8) or CS denervation (G9) in C & U group greatly increased diureSISof RL infUSion (Table Ill). This effect is difficult to explain because it is generally believedthat atrial stretch receplors haVing their afferents in vagi are essential for the IOhibilionof antIdiuretic hormone (AOH) production and to causo dlUfesls. which disappears aftervagotomy (5,8·11,23.26). Vagotomy, occlusion of common carotids and occlusionof es in the presence of vagotomy increases ADH secretion (22-25). Kappagoda at a/.(11) has reported that diuresis reSUlting from atrial stretch is not due to fall in ADH concent­ration. Others have also shown that saline induced diuresis is not affected by ADH andaldosterone concentration or their administration (1.33), Thus. il would nppecr fromthe available literature that the exact mechanism of saline induced diuresis IS far from

clear.

Combined vagotomy and CS denervation (G10) decreased diuretic response toinfusion even below the intact (G5), vagotomlsed (G8) or es denervated (G9) groups.

•

•

Dluresll dutl,..a Fluid I""ullon 167

This fall in diuretic response might be due to an increased AOH production in the absence

of both vagat and CS afferent inhibition (22-25). Hence, it appears that even if one ofthese two pathways are intact as in G8 or G9, the AOH secretion in response to infUSIonof Rl is tess. But when both types of influences are absent its secretion IS more. Secondpossibility of the decreased diuresis in Gl0 is perhaps due to extreme vasoconstriction(31) resulting after removal of vagal and CS inhibitory impulse to sympathelic vasomotorlone which is high in renal vessels.

The urine flow rate of spinal dogs (G 11 and G12) was almost equal to intact PlOgroups (G1 and G2. Table III). Vagotomised spinal dogs (G12) had signIficantly morediuresis than spinal dogs (Gl1). In both groups. appreciable urine flow rate was seenafter 30 to 35 ml infusion stages when their reponed blood Pfessure (BP) was 50 to 60 mmHg (31) and cont noed till the end of infusion schedule indicating that the renal funcbonsin spinal dogs was re-established at 50 to 60 mm Hg. In spinal dogs (Gll). there wasanuria at 30 min after the completion of the infusion schedule when their reported BPwas 35 mm Hg (31) mdicatlng the rena' failure. Renal blood flow and glomerular hit­rallon falls dUlIng haemorrhaglc hypotenSIon (2.4) and eXtreme oltouna and anuna occurat 40 to 60 mm Hg BP (20) and urine flow begin at about 60 mm Hg of renal perfusionpressure (27) The present observation suppens these data but the regressIOn pattern ofdiureSIS could not be compared as there are no published reportS on thiS.

ACKNOWLEDGEMENTS

The authors gratefully acknowledge the physical facilities provided by the autho­n::es of the St. John's MedIcal College. Bangalore and the Veterinary College. Bangaloreto carry out this work. and that of Or. N. SunderraJ and Mr. E. Vasantha Kumar of the Uni­versIty of Agricultural SCIences, Banga/ore. for their kind help in the statistIcal analYSIS

REFERENCES

eO/1n.v. M A, M Myll•. W.e. Lesslt., .nd W.W. GOI1,sch.lk. Ren.1 tubul... Ir.nsporl 01 wetor. lolute .nd PAHI'" r.u 10lded with IlOlomc ullne. Am. J. Physiol, 2ft' , 1199·1205.1965.

2. Goodyer, A.V.N. Ind CA. Jleoer Re,...l response to non·shocklng h.ernorrh.g.: Roll 01 .ulonomic nervoussysrem .nd of the renel cllculello,... Am. J. Physiol.. 180 : 69·74. 1955.

3 Grove. O. Uber die Elgen'thellen des Kokosrubwassers. Tropen/,md."m.": 37·57.1967.4. Helneffllnn. H.D" C.M. Smythe Ind P.A. Marks. Effecl of tlaemoutl.ge on eSllmlled IHIPIIIC blood !low and

renal blood Ilow In dogs. Am. J. Phys;oI.• 174 : 352·356. 1963.5 Henry. J P. end J.W. Purce. The possible role of cardlllC alrial stretch receplors In the lnduttlon of change irl

~llne flow J. PhysU" 131 : 672·1)85, 1956.6. Jagger. P.I. D.P. Lauler and G.W. Thorn. Sali,...·induced nalriufosis. Fed. P,oc., 24 : 404, 1966.

7. Jones. L.M Vtll,nnlry PhlrmKOlogy .,..d Therapeutic$. 2nd Edn. Ames. low•. Th. low. Sl. UnN. Press.~p. 127 130, 1957.

8 I(.ppagod•. CT. R J. Unclen .nd H.M. S"ow. A reflelt incruse I,.. h.all file from dlSler.llon 01 Ih. iunctlo,..betw'en the IUplfior V'".CIY••,..d Ihe flghl .uium. J. PhyslOl" 220 : 171·197. 1972.

9. Keppegod•. C T , R.J Untlen and H.M. Snow. The e/feet 01 dlsle,..ding the Ilfi.l .ppendllges 0" u",... llowin Ih. dog. J, P"'#4.:>1~ 221 : 233 242. 1972.

lO'10.

11.

12.13.

"15.

1~

17.

18.

19

,0.

21.

22.

,3.

25.

28.

28

28.

30.

31.

n.

33.

SUlesh Ind Sn,rm. Jul Septomber 1919lnd J Phys,ol. Phllrm."'.

lC'pplOod•• C.T.• R.J. Linden and H.M. Snow. The effecl of suelchlOO Ihl lUptll'ior v.nae.v.l - right "'I"junction on right .ttl,1 receptor in lhe dog. J. Physiol~ 211 : 875-887. 1972.Kappagoa.. C.T.• R J. Unaan, EM. Scali .od H.M. Snow. The elhlfefll P'lhw~ of th' III~x ,ncrl'M In he,nr,tl pro6u~d by stimuladon of lelt ,tll,l receptors. J. Phyvol~ 242 : 79. 1974.

IGdd. C.. J.R. LtdIOfM.nd R.J. UnOeo. Atri'l fe<:eptOfS and thl hurl III,. J. Ph'(J#JI.• , •• : 78·79P. 19GI.

LeoMllTlt. J.R.• R.J. UI1den .nd W.J. O·Conner. The m8charn&m try whlctl d'llen$lon 01/.11 IUlum producesdIU"" 'n lnM5ltlellMd dogs.. J. Phy.sKJI~ 10 : 87-100. 1981

Leo.inslr:y. N G. .Nt R.C. ulone. The mechanism of sodium dlUN$ls alt. s.a4lne .nluttQn 1ft tht dog J elm.IlIwwt.. U : 1261-1278. 1863

"''''. E.. C.R.M. FIedwoo<l end A. Sthwettz«. Preuor responses 10 elecll'oea!lUmullbon 01 tM ~otld """'.,*",,1" CltS. J. PIrysioI~ ,. ; 25'-271. If,49.~. E.. C R.M. Redwood and A.~~. EffllC1 01 EJeevjeal l'llmul.\JOll of IOtlle ~ 011 bIoocl oresaweM>d raporrion in c.a tod 'lItlblb uo6ef chIot.tow lind nembul.lll 't1_m... J. PfrpIOI~ 1. : 392. 19'9l\Iocnob. J.G..nd J.P. Qv,lllllm. The"*~ of aetJOIl of J*.ldtohydll! lind mel~tynol011 ~omua<:UIlIr

u""lmIIIion. Bot. J PhlIrtrI«:oI. C"--~ 11 : 151-155. 1956Papptr. S. L Soon. J P. RoMnbwm and H.W. Cohen. EffectS 01 osotonlC 'nd h\1)ertotUc Mil ~I>onS on1)" reMI excretlon of 1odIum. J. (lib. eM. Med~ 47 : 776·712. "58RaIU. LG. Dexv.n 'nd~:'"_ pl_ volume e~ndIn; "nlll eXCJtiUOtl and ,Il.as on~ funebon.J. LMl. CJIII. M«J. 4e : 880-890. 1'52.

s.nn.t. E Eo R.nal~ !low and 'eMf dearlInce duril'lO~c shock. AnI. J. PIt'fSlOl~ 1.1 : 899­709. lt48$e1klM't. LE The renal O'cua.bon.. In: HlIIIdbook 01 Ph~ S«uon II. Corculauon. Vat II. AM~. Sot•• WQhlnpOtl. 0 C. SIP. 1457-1516. 1963.Share. L and M N leYy. C.d1O¥hCU" receptors and blood lll*' of the .ntJd!u"etae hormone. Am. J. PhyM)I..20S : ·426·428. 1'82S'*-o L Effect 01 c.olId l'mUl ocdullOll on lefl amal d11!etlSion and p1aune~..n.. Am. J. PltplOl~

ZU : 219-223. 1985

Shiite. L and M.N Levy. Effect of ClIfolld chtinoreceplor $tIl'IIUI.I4or'I on pAnma anbdJurellc h(ll'motM! lJl.AnI. J. P1tp#o/~ :no : 157·181, 1866.

sn-e. L and U.N. levy CMolld &lnut pulM pressute. a de1¥ml....nl 01 plasma anbdl.nbC hortnorle l;Ofll»l\l.ra\lOft. Am. J. Ph-plOl. 111 : 721·724. 1966

Shere. L Role 01 pcr'P'*al '~1Or1 ,n the increllsed tele.ue of vesoprew" on '1:SPOJ'l" 10 hMlnQfTl\ag4.EndoctIMJkJgy.11 11140-1148.1987.

Stilpley. R E. .nd R.S. Study. Changes In renal blood flow. Db'ClIon of ,nubn. gIomarlll., 1.lua\JOll rale. I'"uept"ftSUl. and uri". flow W1lh lIeula aJlefauonl 01 rlitl'W artefY blood press....... Am. J. PhysKJI~ 1.1 : 678-688.1951.

SMdecor. OW. and W 0 Cochran. SI.'IJtICM Merhods.. Edn. 6 Calcuua. Ollford .nd ISH Publ Co. PI)94. 100. 115. 271. 298·298 and 460·464. 1968.

Sur-llih. T.P.. V Ravrvarrra H'Ode. S V S Sh.lly and T A S Ra.lOolchar. FluId lherllpy by londer eOCOtlut Wal/lfIn ve'lrinary pt"toedce. Incltllll VeL J~ 41 ; 829·837.1968

SWIsh T.P. and V. Raviv.rml Hedge. Tend., coconut wiler IS a pluma volume ellp'nd,,: II. Studtes 011physiological re.pon"l. MYJexe J. Agile. SCI. I : 410-422. 1971.

Sutuh, T.P. Nautili conuol 01 cerdiovascular funclions Elleel of volume change. Ph O. Th"ls. SangalOl'Unlvershy. Bangalora. 1916.

Surelh, T P. R,gr...lon pella," 01 amplitude of electrocardlogrll:phlc WlI:VU durlllg 1llllavllnou. Inlulion Inintacl, bufllll nerv' dentlrv,led and spinal dogs. Ind. J. PhYSlol. PllafmlJc.. 2Z : 249·262.1978.WIlIIOn. J F. EII'el of Ullino loading on sodium ,eabsorpl,on In th. dog prOlllmlll Il.lbule. Am. J. PhyStOI..110 : 781·785. 1966.