EFFECT OF FSH AND INSULIN ON LIPOGENESIS IN CULTURES OF SERTOLI CELLSFROM IMMATURE RATS

Follicle-stimulating hormone (FSH) and insulin regulate glycide metabo lism in Sertoli cells, thus stimulating lactate production. These stim ulatory effects of FSH and insulin do not require protein synthesis, s uggesting a modulation of enzyme activity and/or regulation of glucose transport. The present investigation was performed to characterize th e hormonal control of lipid metabolism in Sertoli cells. The data indi cate that FSH and insulin have a regulatory effect on lipid metabolism in Sertoli cells, After 8 h of preincubation with insulin (5 mu g/ml) , the activity of the enzyme ATP-citrate lyase in cultured Sertoli cel ls was increased from 0.19 to 0.34 nmol NAD(+) formed mu g protein(-1) min(-1). FSH (100 ng/ml) had no effect on this enzyme. Glycerol phosp hate dehydrogenase activity was not affected by any of the hormones te sted. When Sertoli cells from 19-day old rats were incubated with [1,2 -C-14]acetate for 90 or 360 min, the [C-14] label was present predomin antly in triglyceride and phospholipid fractions with minor amounts in other lipids. In Sertoli cells pretreated for 16 h with insulin and F SH, an increase in acetate incorporation into lipids was observed. Mos t of the label was in esterified lipids and this percentage increased with the time of treatment; this increase was remarkable in triglyceri des of control cells (18.8% to 30.6%). Since Sertoli cell triglyceride s participate in the control of spermatogenesis, the present data sugg est that the hormonal control of lipid metabolism in Sertoli cells is important not only for maintaining the energy of the cell itself, but also for the control of the spermatogenesis process.