Follicle-stimulating hormone-induced lactate secretion by cultured sertoli cells does not require extracellular calcium

Sertoli cells of the testis secrete lactate in response to follicle-stimulating hormone (FSH). It is thought that the developing germ cells use lactate as an energy substrate preferentially over glucose. However, the biochemical mechanism(s) involved in the regulation of lactate secretion in response to FSH are unknown. The purpose of this study was to determine if extracellular calcium was important for the actions of FSH during this response. It was found that the FSH-induced increase in lactate production by Sertoli cells was not dependent upon the presence of extracellular calcium. However, A23187 (a calcium ionophore) stimulated lactate secretion in the presence of extracellular calcium. When FSH and A23187 were tested together at maximal concentrations, more lactate was secreted than when either FSH or A23187 was tested alone. Neither verapamil, nifedipine nor diltiazem (calcium channel "blockers") were able to inhibit the ability of FSH to increase lactate secretion. These results indicate that FSH-induced secretion of lactate by cultured Sertoli cells is not dependent upon extracellular calcium.