I N T E R N A T I O N A L J O U R N A L O F A N D R O L O G Y

1 (1978) 563-569

Department of Physiology, Raja Peary Mohan College, Uttarpara, Hooghly, W e s t Bengal 712258, India

The Possible Mode of Action of Prostaglandins. XV. Study of the Ef fec t o f Prostaglandins El , EB or FBa

in Limiting the Fertilizing Capacity of Epididymal Spermatozoa in Rats’)

BY

Amar Chatterjee and Swapan K . Rej

Multiple sc injections of prostaglandin El and prostaglandin E, a t a dose ot 5 mgikg and 10 mgikg b. w., respectively on days 8, 10 and 12 or 15, 17 and 19 following surgical separation of epididymides from the testes a t the testis-caput junction made the test animals infertile. Prostaglandin F,, conversely failed to affect the fertility in the same experimental model system at a dose of 2.5 mgikg. Testosterone replace- ment concurrently with prostaglandin El or E, effectively maintained the fertilizing ability of the epididymal spermatozoa in all of the test animals. The possible involvement of prostaglandins in affecting the fertilizing capacity of the epididymal spermatozoa has been discussed.

Key words: prostaglandin El - prostaglandin E, - prostaglandin F,,, - epididymal spermatozoa - fertilizing capacity - male rat.

Since the report of Horton that human semen is the richest vertebrate source ccntaining at least 1 3 different prostaglandins (PGs) (see Kelly 1978) it has been speculated that PGs might contribute to the female tract (Mandle 1972). Several reports have claimed that there is a correlation between low PG levels and unexplained infertility (Bygdeman et al. 1970; Collier et al. 1975). By

1 ) The expenses of this investigation were defrayed by research grants from the Indian Council of Medical Research, Family Planning Foundation, India; and the World Health Organizatioa (Human Reproduction Unit, Small Supplies Programme).

Received on August 7th, 1978.

563

using bioassay technique Sturde (1968) has further shown that the PG content of the human semen is androgen dependent which has been again confirmed by chemical tests (Skakkeback et al. 1976).

Recently a broad spectrum of pharmacological effects of exogenous PGs have been reported. Among them are inhibiticn of spermatogenesis (Ericsson 1972), suppression of steroidogenesis (Rartke et al. 1973) leading to lowering of plasma testosterone (Saksena et al. 1973) and depression of LH and FSH (Kimball et al. 1978). This paper reports a comparative study concerning the efficacy of PGE1, PGF2 or I’GF?, in altering the fertilizing capacityof of the epididymal spermatozoa.

Materials and Methods Laboratory bred (Wistar) fertile male rats (240-260 g) were housed at a con- trolled lighting schedule cf 12 h light per day and had free access to food pellets and water. Epididymides of the rats were surgically separated under light ether anaesthesia at the testis-caput junction taking care to leave the blood vasculature supplying the testis and epididymis intact.

PGE1, PGEz and PGF.I,<, kindly donated by Dr. J. E. Pike of Upjohn Com- pany, Michigan, USA were dissolved in 96 O/O ethanol (10 mgiml) and diluted with saline 1:9) before use. PGs were injected subcutaneously (sc) in groups of animals a t a dose of 5 mg/kg (PGEl), 10 mgikg (PGE2) and 2.5 mgikg (PGFa,). Testosterone in oil (“Perandren” - Ciba) was injected sc at a dose of 100 gg i ratiday (Table 1).

Cyclic females on the day of their vaginal pro-oestrus were paired overnight with the test males. Presence of spermatozoa in the cestrous vaginal smear or vaginal plug was considered as an index of day 1 of pregnancy. On day 8 p. c. laparotomy was performed on the mated females to reconfirm pregnancy by locating the presence of implantation site(s). Animals were sacrificed 30 days following the surgical manipulation of the epididymis. At autopsy, testes, epi- didymis, seminal vesicles and prostates were removed, freed of their adhering tissues, weighed on a torsion balance and compared with the controls using Student’s t-test.

Results The fertilizing capacity of the surgically manipulated epididymal spermato- zoa was found to be retained for about 3 weeks. Mating with these animals was found to be fertile anytime between the first week and thiqd week following the operation. Mating during the fourth week was recorded to be infertile, but the mated females became pseudopregnant, an indication of keeping sexual

564

activity of the animals intact without retaining the potential fertilizing capacity c;f the epididymal spermatozoa. Tables I and 2 show that a multiple dose sche- dule of PGE, on days 3. 5 and 7 in the surgically manipulated animals re- tained fertility up to the third week. The weight of the testis, however, was recorded to be significantly lowered (P < 0.005), but not that of the other accessory sex glands. The same PGEl regimen either on days 8, 10 and 12 or 15, 1 7 and 19 consistently affected the fertility and the animals of both the test groups became infertile. Testes cf these animals were also found signi- ficantly regressed (P < 0.05; 0.01) leaving the accesscry sex glands unaltered. PGE-, when similarly programmed like that of the previous experiments re- sulted in identical changes in terms of fertility, however, neither the testis nor

Tablc I . Effect of prostaglandin El , E, or F,, on the fertilizing ability of the

epididymal spermatozoa.

Treatment

Operated control

Operated+ PGE, (days 3, 5 , 7)

Operated + PGE, (days 8, 10, 12)

Operated+PGEl (days 15, 17, 19)

Operated+PGE2 (days 3, 5 , 7)

Operated+PGEg (days 8, 10, 12)

Operated + PGE, (days 15, 17, 19)

Operated + PGF,, (days 9, 5 , 7)

Operated + PGF,, (days 8, 10, 12)

Operated + PGF,, (days 15, 17, 19)

Operated+PGEl (days 15, 17, 19) -1 Testosterone (days 15-19)

Operated+PGE2 (days 15, 17, 19) +Testosterone (days 15-19)

Mating records (week following operation)

2nd week 1st week (pregnantiused)

-

616 (100 O/n)

-

I

10110 (100010)

G/6 (100 "in)

oil0 ( 1 0 O o 1 o failure)

-

515 (100 010)

018 (100 010

failure)

-

515 (100 010)

515 (1000,'n)

10i10 (100"io)

616 (100 O/o)

Oil0 (100% failure)

018 (100 O/o

failure)

515 (100 V O )

018 (100 O/o

failure)

016 (100 "/a

failure)

515 (100~10)

51.5 (100 O i n )

515 (100 " i n ) 9 5 (100 "10) - 10110 (100"/0)

- 81'8 (100 O/o)

565

Table 2. Organ weight (mg/100 g b.w.) of the prostaglandin- or prostaglandin with testosterone- treated male rats having surgically separated cpididymides as used in fertility tests.

Animals were sacrificed 30 days after operation.

Treatment

I I Mean Mean

testicular wt. epididymis wt. (mg k SE) (mg k SE)

Operated control

Operated + PGE, (days 3, 5, 7 )

Operated + PGE, (days 8, 10, 12)

Operated + PGE, (days 15, 17, 19)

Operated + PGE, (days 3, 5, 7)

Operated + PGE, (days 8, 10, 12)

Operated + PGE, (days 15, 1 7 , 19)

Operated + PGF2,z (days 3, 5, 7 )

Operated + PGF,, (days 8, 10, 12)

Operated + PGF,,L (days 15, 17, 19)

Operated + PGE, (days 15, 17, 19) t Testosterone (days 15-19)

Operated + PGEz (days 15, 17, 19 )+ Testosterone (days 15-19)

671.6 f 40.0 190.6 f. 6.1

489.5 f 28.5 186.0 f 19.4 (P < 0.005)

(P < 0.05)

(P < 0.01)

482.2 k 82.4 191.0 2 7.6

414.4 * 63.0 172.2 k 8.4

730.2 k 80.2 203.9 f 46.0

641.6 * 93.0 200.0 f 15.9

606.3 f 67.1 195.2 f 17.4

584.9 k 113.0 191.8 f 13.2

571.4 * 69.9 210.8 k 21.0

572.3 f 50.6 204.6 f 14.8

414.4 f 8.3 187.1 f 3.8 (P < 0.001)

693.0 ? 90.0 220.3 k 47.5

Mean sem. vesicle wt.

(mg k S E )

Mean prostate wt. (mg k S E )

154.0 k 14.8

150.3 k 26.0

126.3 k 15.0

155.7 k 42.2

159.2 f 3.4 179.3 k 51.9

149.9 f 20.9 129.7 k 18.6

187.2 k 37.2 129.4 k 24.2

139.5 k 19.2 156.0 f 17.5

144.5 k 19.3 139.1 k 18.5

134.3 f 20.0 145.8 f 19.5

133.1 k 11.8 152.7 k 17.7

121.6 f 19.9 120.8 k 7.2

180.6 f 18.3 143.8 k 16.0

161.8 f 10.2 137.8 f 10.7

566

the accessory sex glands showed any appreciable change in weight compared to controls (Tables 1 and 2). PGFi, regimen, on the other hand, did not show any detectable change in fertility or organ weight in any of the test groups (Tables 1 and 2). The maintenance of weight of the accessory sex glands, but loss of fertility by PGEl or PGEe in the surgically manipulated experimental animals could be explained as due to an inappropriate availability of androgen, since it is evident that PGs effectively block steroidogenesis (Bartke et al. 1973; Saksena et al. 1973).

Therefore, further experiments were designed to explore the possible involve- ment of testosterone to normalize the deleterious influence of PGEl or PGE; on the fertilizing capacity of the epididymal spermatozoa. It was observed that an addition of testosterone regimen concurrently with PGEl or PGEZ prevented the hazardous effect of PGs and consistently maintained the epididymal sperm viability and fertilizing capacity (Table l) , but failed to reverse the regression in testicular weight as found following treatment with PGs (Ericsson 1972; Menon 1973).

Discussion The loss of fertility as found in our experimental rats having PGEl or PGEz cn days 8, 10 and 12 or 15, 17 and 19 and its reversal following testosterone supplementation seems to be due to YG-induced blockage of steroidogenesis (Bartke et al. 1973: Saksena et al. 1973), because the structural and functional integrity of the epididymis are androgen dependent (Risky 1963) and sperm maturation process has been shown to occur in a high androgen environment (Lubicz-Nawrocki 1974).

It has been further decumented that the epididymal spermatozoa loose their fertilizing ability 3 days after castration or 4 days following hypophysectomy. Testcsterone, however, prevents the effect of castration or hypophysectomy (Dyson & Orgebin-Crist 1973). Failure of PGF;, in altering the fertility in our surgically manipulated experimental rats is well compromizing with the views cf Lubicz-Nawrocki et al. (1973) that the dose schedule of PGF2a used does not effectively minimize the plasma levels of testosterone. Our recent experience using different intratesticular doses of PGs reveal that even at the dose level of 2 mgikg, only PGEs are effective in altering fertility and inducing testicular regression, but PGF;, does not.

The failure of testosterone to minimize the weight loss following PGEl schedule in one experimental group could be explained either in terms of its effect in lowering the blood flow (Free & Jaffe 1972) or by lowering the levels of serum gonadotrophins (LH and FSH) as recently reported (Kimball et al. 1978). However, the maintenance of fertility by testosterone in the presence of PGEl or PGE; tempts us to support the view of a direct involvement of PGs

567

on stercidcgenesis (Bartke et al. 1973), since PGs are found to depress the serum testcsterone concentrations even in the presence cf increased levels of LH (Bartke et a]. 1973; Tso 1976).

Acknowledgment The encouraging cooperation of Dr. S. Tejuja, Dr. R. T. Mahoney, Dr. S. J. Segal. Dr. A. Bartke, Dr. A. Kessler, Dr. B. I<. Anand and Dr. Nitya Nand is highly appreciated.

References Bartke A,, N . Musto, B. V. Caldwell & H. R. Behrman (1973) Effects of a cholesterol

inhibitor and of prostaglandin F2,i on testis cholesterol and on plasma testosterone in mice. Prostaglandins 3, 97.

Bygdeman M., B. Fredricsson, K. Svanborg R- B. Sarnuelsson (1970) The relation be- tween fertility and prostaglandin content of seminal fluid in man. Fertil. Steril. 21, 622.

Collier J. G., R. L. Flower & S. I,. Stanton (1975) Seminal prostaglandins in infertile men. Fertil. Steril. 26, 868.

Dyson A. L. M. B. & M. C. Orgebin-Crist (1973) Effect of hypophysectomy, castration and androgen replacement upon the fertilizing ability of rat epididynial spermatozoa. Endocrinology 93, 391.

Ericsson R. J. (1972) Prostaglandins (El and EP) and reproduction in the male rat. A d v . Biosc. 9, 737.

Free M. J. & R. A. Jaffe (1972) Effect of prostaglandins Ln blood flow and pressure in the conscious rat. Prostaglandins I , 483.

Kelly R. W. (1978) Prostaglandins in semen. Their occurrence and possible physiolo- gical significance. Znt. /. Androl. 1, 188.

Kimball F. A,, R. D. Frielink & S. E. Porteus (1978) Effects of li(s)-15-methyl prosta- glandin F,, methyl ester-containing silastic disc in male rats. Fcrtil. Steril. 29, 105.

1,ubicz-Nawrocki C. M. (1974) The effect of castration and testcsterone replacement on sperm maturation in the hamster. /. Reprod. Fertil. 37 , 251.

Lubicz-Nawrocki C. M., S. K. Saksena & RII. C. Chang (1973) Effect of prostaglandins El and on the fertilizing ability of hamster spermatczoa. /. Reprod. Fertil. S5, 557.

Mandle J. P. (1972) T h e effect of prostaglandin El on rabbit sperm transport in vivo. /. Reprod. Fertil. 31, 263.

Menon G. N. (1973) Effects of intratesticular injections of prostaglandins on the testes and accessory sex glands of rats. Contraception 8, 361.

Risley P. L. (1963) Physiology of the male accessory organs. In: C. G. Hartman, Ed. Mechanisms Concerned with Contraception, p. 73. Pergamon Press, New York.

Saksena S. K., E. El-Safoury & A. Bartke (1973) Prostaglandin E3 and decrease plasma testosterone levels in male rats. Prostaglandins 4 , 235.

Skakkeback N. E., R. W. Kely & C:. S. Corter (1976) Prostaglandin concentrations in the semen of hfrpogonadal men during treatment with testosterone. J . Reprod. Fut i l . 47 , 119.

568

Sturde H. C. (1968) Experimentelle Untersuchungen zur Fraze der Prostaglandine und

Tso EC-F. (1976) Effects of prostaglandin E, (PGE,) on the male reproductive system ihrer Beziehungen zur niannlichen Fertilitat. Arzneimittel-Foisch. 18, 895.

Contraception 14, 53.

Author’s address: Amar Chatterjee, Department of Physiology, School of Medicine, University of Zambia, P. 0. Box RW. 110, Lusaka, Zambia.

’ 569