Effect of the human follicle-stimulating hormone-binding inhibitor and its N-terminal fragment on follicle-stimulating hormone-induced progesterone secretion by granulosa cells in vitro.

Intrafollicular factors play an important role in folliculogenesis. The follicle-stimulating hormone (FSH)-binding inhibitor (FSHBI), purified by our laboratory from human ovarian follicular fluid, has been shown to suppress ovulation and induce follicular atresia/apoptosis in mice as well as impair fertility in marmosets, the New World monkeys. The octapeptide, a peptide corresponding to the N-terminal region of human FSHBI (hFSHBI), has been synthesized and also shows FSHBI activity in vitro. In the present study, we have attempted to identify the mechanism of action of the peptide in granulosa cell cultures. Rat granulosa cell cultures were treated with varying concentrations of the octapeptide or partially purified hFSHBI (gel chromatography fraction hGF 2) in the presence or absence of human FSH (hFSH) and the amount of progesterone (P;4) secreted in the culture supernatants after 3 h/48 h was estimated. Both hGF2 and the octapeptide failed to alter basal levels as well as 8-bromo cAMP-induced P;4 production, while FSH-induced P 4 secretion was inhibited in a dose-dependent manner. These studies reveal that the octapeptide, a fragment of FSHBI, and the native protein have similar activity in vitro and both compounds alter FSH action at the receptor level upstream of cAMP formation.

Testicular changes due to graded doses of nicotine in albino mice.

Administration of graded doses of nicotine (0.2 mg, 0.4 mg and 0.6 mg/100 g body weight) for 15 days to the adult mice reduced the weight of testis, number of spermatocytes and spermatids, but increased the number of spermatogonia which may be due to reduced conversion to subsequent stages. There is a high cholesterol content and Sudanophilic lipid accumulation in the treated testis. The weight of accessory sex organs which is dependent on androgens produced by the testis is also reduced. These changes are brought because of the non-availability of pituitary gonadotrophins essential for initiation and completion of spermatogenesis and steroidogenesis in the testis due to the administration of nicotine, which being CNS depressor might have caused inhibition in the neural stimulus essential for release of pituitary gonadotrophins.

Effect of passive immunization with specific anti-FSH on tes-ticular lipids and some lipogenic enzymes of adult bonnet monkeys

The effect of anti-follicular stimulating hormone [FSH] on testicular lipid and the specific activity of testicular enzymes of the isocitrate dehydrogenase [ICDH], pyruvate/malate dehydrogenase [MDH] and malic enzyme involved in lipogenesis were studied in mature bonnet monkeys, Macaca radiata. Immunization of monkey with anti-FSH for 24 days did not produce any significant changes in the body weight, organ weight and pituitary weight. Testicular isocitrate dehydrogenase [ICDH] and malic enzyme activities were decreased significantly but MDH activity was stimulated by anti-FSH treatment. Testicular total lipid, phospholipid and cholesterol, were not altered significantly by the Anti-FSH treatment. Increased level of free cholesterol were also observed after FSH treatment. Among glyceride glycerol sub classes, triacyl glycerol showed a significant increase. Among testicular phospholipid classes, phosphatidyl inositol was markedly decreased by anti-FSH immunization. Data on serum hormonal profile, shows that there were no alteration in serum testosterone, prolactin [PRL] and luteinizing hormones [LH] but FSH was significantly decreased. The present study reveals that immunization with anti-FSH has significant effect on different class of testicular lipids and pyruvate malate enzymes cycle

Does inhibin have intrinsic prolactin suppressing activity?

Evidence to demonstrate suppressive effect of inhibin on prolactin has been presented. The inhibin preparations derived from human testicular tissue, human seminal plasma and porcine follicular fluid were tested and all the three preparations were found to exhibit prolactin suppressing activity.