PARENT SESSION
MECHANISMS OF HORMONE ACTION
Harborside C
7:30 AM-10:00 AM

(587) FSH IS NOT REQUIRED FOR THE ELEVATION OF FUNCTIONAL ACTIVITY OF MONKEY SERTOLI CELLS.

Sangeetadevi, Yendrembam¹, Sarda, Kanchan¹, Majumdar, Subeer¹, ¹ Primate Research Centre, New Delhi, IN

ABSTRACT- It is believed that both FSH and LH, the latter acting through testosterone (T), provide endocrine stimulation to the testicular Sertoli cells (Sc) for the regulation of spermatogenesis. Most of the studies of hormonal regulation of Sc function were performed using rats. However, results obtained from rat studies cannot always be extrapolated to primates due to differences in their hypothalamic-pituitary-testicular axis. Hence, it is necessary to study primate Sc function and their hormonal regulation. Since Sc posses receptors for FSH and necessity of FSH in spermatogenesis is a matter of debate, we studied the role of FSH in modulation of primate Sc function. For this purpose, we cultured Sc from juvenile bonnet monkeys (Macaca radiata). For comparison, we also cultured Sc from 18-day-old rats. Lactate, produced by Sc, is a known substrate for the germ cells. In agreement with previous studies, rat Sc produced lactate, which was significantly (p<0.05) augmented by addition of oFSH. In contrast to this, basal lactate production rate of monkey Sc was not augmented by recombinant (r) hFSH. Such elevated levels (16-fold as compared to rat) of lactate limited the scope of FSH to stimulate it further. Treatment of rat Sc with rhFSH resulted into significant (p<0.05) rise in lactate production, implying rhFSH was bioactive. This autoaugmentation of lactate production by monkey Sc in the absence of FSH necessitated investigation of other functional parameters of Sc. To this end, aromatizing ability of Sc was evaluated. In concurrence with earlier reports, there was no discernible rise in estradiol when rat Sc were exposed to T alone (T used as a substrate) but addition of FSH to this experimental paradigm resulted into significant (p<0.01) rise in aromatizing ability. Based on information regarding lactate production rate, one would speculate the aromatase activity of monkey Sc to be at its peak even in absence of FSH. In agreement with this notion, monkey Sc significantly (p<0.01) converted T to estradiol without addition of FSH and FSH treatment failed to induce further rise in the levels of estradiol, confirming that FSH is not required to elevate functional activity of cultured monkey Sc.

KEY WORDS: FSH, Sertoli cells, Primate, Aromatase