Vitamin D modulates the effects of follicle-stimulating hormone of sertoli cell function and testicular growth in siberian hamsters

Abstract

Sertoli cells from immature (18–20 day old) Siberian hamsters (Phodopus sungorus) raised in a long photoperiod (LD; 16hL : 8hD) or a short photoperiod (SD; 6hL : 18hD) were cultured and exposed to follicle-stimulating hormone (FSH) and/or vitamin D₃ (D₃) in vitro. D₃ did not stimulate lactate production when added alone, but significantly augmented the stimulatory action of FSH on lactate production by Sertoli cells from both LD- and SD-exposed hamsters. Hamsters raised in LD or SD were injected daily with D₃ for 10 days starting at 18 days of age. This treatment resulted in a significant increase in the testicular weight of hamsters raised in LD in which circulating FSH levels are high. In contrast, testicular weight was not altered by D₃ treatment in SD hamsters in which circulating levels of FSH are low. We conclude that D₃, probably after hydroxylation to 1,25(OH)₂ vitamin D₃, modulates the action of FSH on testicular growth and Sertoli cell function.