Effect of Starvation on Gonadotropin Secretion in Intact and Castrated Male Rats

Abstract

The effect of starvation on serum and pituitary concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was studied in intact and in castrated 4-month-old male rats. In intact rats, starvation for 7 days resulted in lower serum FSH (P < 0.05) and LH (P < 0.01) levels than in fed controls. Body, pituitary, and ventral prostate weights were also lower (P < 0.01) in rats starved for 7 days than in controls. The starvation-induced reductions in the serum levels of FSH and LH occurred within 48 and 24 h, respectively, after food was withheld. Rats subjected to starvation for 7 days immediately following castration showed higher (P < 0.05) pituitary concentrations of both FSH and LH than fed castrates. The serum levels of FSH and LH were equally high in both groups of castrates.The results suggest that starvation results in a rapid inhibition of gonadotropin secretion and the inhibition is dependent on an intact negative-feedback system.