FSH stimulation of the production of pyruvate and lactate by rat Sertoli cells may be involved in hormonal regulation of spermatogenesis.

Abstract

Summary. Sertoli cells were obtained from 3\p=n-\6-week-oldrats, which were sterile after prenatal irradiation. The production of lactate by these Sertoli cells, measured 24\p=n-\48h after isolation during incubation in the absence of hormones, increased with age of the rats from 3 to 6 weeks. At all ages investigated, the production of lactate was enhanced in the presence of FSH plus testosterone, but the stimulation was most pronounced at 4 weeks of age. Lactate production was increased by FSH alone but testosterone had no effect in the presence or absence of FSH. Sertoli cells from 4-week-old rats produced both pyruvate and lactate, which accumulated in the incubation medium in a ratio of 1:4. The stimulation of the production of pyruvate and lactate by FSH was dose\x=req- dependent (ED50 at ~10 ng NIH-FSH-S13/ml). The production of pyruvate and lactate was stimulated 2-fold by insulin, 4-fold by FSH and > 6-fold by dibutyryl cyclic AMP (in the presence of 3-isobutyl-1-methylxanthine). The effects of FSH (0\m=.\5\g=m\g NIH-FSH-S13/ml) and insulin (5 \g=m\g/ml) were not additive. Leucine incorporation into isolated pachytene spermatocytes and round spermatids was stimulated by exogenous pyruvate and lactate in a dose-dependent way : maximal incorporation was obtained with 0\m=.\2 mM-pyruvate or 2 mM L-lactate. Spent medium from incubated Sertoli cells (from 4-week-old rats) stimulated the leucine incorporation into isolated pachytene spermatocytes and round spermatids 4\p=n-\8-fold.This effect could be explained by the amounts of pyruvate and lactate present in the spent medium. It is suggested that pyruvate and lactate are major products from Sertoli cells which can support synthetic activities in germ cells, and the present results indicate that pyruvate and lactate may play a role in the hormonal regulation of spermatogenesis.