877
Abstracts
314. Effect of ocular oaf intnmuwuhr admiaktration of estradiol on serum testosterone levek in adult male rhesus monkeys SEHGAL. A. and ANAND KUMAR. T. C.. Neuroendocrine Research Laboratory. Department of Anatomy. All India Institute of Medical Sctences. New DelhiIloOl6. India 10~8 and 1OO~g of estradiol (El. dissolved in a mixture of ethanol:propylcne plycol:water (3:3:4). was administered as eye drops to adult male rhesus monkeys. Follow~ng a period of 8 weeks of recovery. similar amounts of steriods were administered intramuscularly. Serum levels of testosterone and estradiol were measured by radioimmun~ssay in venous blood samples collected at intervals of 20 min for I h. prior to treatment. after control (solvent) treatment and after estradiol treatment. In addition, their levels were measured in blood samples collected 24 h after estradiol administration. Testosterone levels had significantly dropped in all the animals 24 h after treatment with the steroid by the twa routes. However. the levels of testosterone were significantly lower following ocular administration of E as compared with the systemic route of administration. These data indicate that the ocular route is more effective in suppressing the levels of testosterone as compared wtth the systemic route of administration.
315. The effect of androgen deprivation un the ultrastructure
of the ~~yrn~
in the
murkkey
PRAKASH. A. and ANAND KUMAR, T. C.. Neuroendocrine Research Laboratory. Department of Anatomy, All-India Institute of Medical Sciences, New DelhiIlOO16. India The epididymis is known to play an important role in sperm maturation. It is also known that the function of the epididymls is dependent on testicular androgens. It is on the basis of this knowledge that the epididymis has been identified as a site vulnerable to extraneous intervention for purposes of ferttility regulation. Cyproterone acetate (CA). an antiandrogen. has been used in clinical trials for impairing male fertility by affecting epididymal function. The present study was carried out on the ultrastructure of the epididymis in order to compare the effects of androgen deprivation by administering CA, with those caused by orchidectomy. The results of this study have shown that the ultrastructural changes observed following castration and CA treatment are consistent with the view
that the absorptive dymis are impaired.
and secretory functions of the epidiHowever. the changes observed in the
CA-treated animals were less severe than those observed following castration. The electron micrographs to be displayed in this Poster Session illustrate details of the ultrastructural changes which have led to this broad general conclusion.
of oestradii17$ nad proteins by is&ted Sertoli cells: effects of serum oud ittcthtion temper&we
316. Sex&on
ROMMERTS. F. F. G., GRWITECOED. J. A.. DE JONG. F. H. & VAN DER MOLEN. H. J., Department of Biochemistry (Division of Chemical Endocrinology). Erasmus University Rotterdam. The Netherla~s lntratesticular
formation
of oestradiol-17/?
12. STEROIDS IN BRAIN AND NEUROENDOCRINE 317. Prugestirttatget celk in rat hia 4 pihtitary SAR. M. and STUMPF, W. E.. Departments of Anatomy and Pharmacology. Chapel Hill. North
University of North Carolina 27514, U.S.A.
Carolina,
(Ez)
in imma-
ture rats can probably only occur in the Sertoli cells from testosterone (T) produced by the Leydig cells. Factors which may regulate the activity of isolated Sertoli cells have been investigated for a better understanding of testicular E2 production. Addition of FSH to isolated Sertoli cells in culture stimulated the production and secretion of E2 from added T more than g-fold. Secretion of proteins. including androgen binding protein (ABP) was stirnu~t~ 2-fold by FSH. Sertoli cells in the presence of T, without added FSH, only secreted small amounts of E, although secretion of ABP and of [‘HI-labelled proteins from [3H]-leucine was stimulated as in the presence of FSH. The secretion of [3H]-la~ll~ proteins was also stimulated 2-fold when cells were cultured in medium containing I’!;, foetal calf serum or I?:, chicken serum. but E2 secretion was stimulated (S-fold) only in the presence of foetal calf serum. Steroid and FSH concentrations in the sera were too low to explain the e&t on Ez secretion. A dialyzablc factor with a M.W. < 5,GQO could stimulate E2 production by Sertoli cells in the presence of T. Sertoli cells incubated for 6 days at 37 C in the presence of FSH and T secreted 4-fold more E, and 2-fold more 13H‘I-labellcd oroteins at day 6 compared to cells incuba& a< 32 C with the same hormones. This effect of temperature on E, production was not present when cells were incubated with I’:;, foetal calf serum. No effect of temperature on ABP secretion by cells stimulated with FSH and T could be observed at the 6th day of the culture, whereas the ABP secretion at the 1st day of the culture was stimulated 2-fold. It is cop: eluded, that in addition to FSH and androgens. other cor+q: pounds and temperature can regulate the activity of Sertdi cells.
FUNCTION
identified as LH secreting cells. The results progestin target sites in the brain and pituitary a direct action of progesterone at the level hypothalamic region and the pituitary as well.
demonstrate and suggest of preoptic(PHS Grant
No. 2-ROI-NS~914.) Cellular localization of progestin in rat brain and pituitary was investigated by the use of thaw-mount autoradiography developed in our laboratory. Twenty-four-day-old rats, castrated and adrenalectomized, primed with 10~~ of estradiol-178 daily for 5 days were kach injected wit6 0.75 ue wr 100 P body weiaht of f3Hl-R-5020, a svnthetic progestin, S.A. ii6 Ci/mM. Autorahio&ams prepared from brain and pituitary showed a nuclear concentration af radioactivity in certain cells which was inhibited by prior administration of unlabeled R-5020. Areas of accumulation of progestin ~n~ntrating cells in the brain include certain nuclear groups in the preoptic and hypothalamic region. In the anterior pituitary progestin-concentrating cells are
318. Tke effects of castration and aging on osmoreplation
in tbe rat VALIQUETTE, G.* Endocrinology,
and MARTINI L., University of Milano,
Department Italy
of
To test whether testicular steroid deprivation and aging might modulate ADH response to dehydration. adult (18&200 g) male Sprague-Dawley rats, either intact or castrated, were kept for 3 or 10 weeks, and then sacrificed after 48 h of water deprivation. PIasma ADH was assayed by RIA, and plasma osmolarity by freezing point depres-