Background: Ghrelin decreases the secretion of LH probably by suppressing the release of hypothalamic GnRH. So far however, there is no evidence that ghrelin affects also the secretion of FSH in humans, the other gonadotrophin regulated by GnRH.
Objective: Our objective was to study the effect of ghrelin on secretion of FSH in humans. DESIGN/STUDY SUBJECTS: Nocturnal (20:00-07:00 h) secretion profiles of FSH were measured in 10 healthy males (25.3 +/- 3.2 years) twice, receiving 50 microg ghrelin or placebo at 22:00, 23:00, 24:00, and 01:00 h, in this single-blind, randomized, cross-over study.
Results: Mean FSH plasma levels were significantly (P < 0.05) lower with ghrelin than placebo between 01:00 and 02:20. Consistently, a significant decrease from baseline was only observed in the ghrelin but not in the placebo condition.
Conclusion: This study provides first evidence that ghrelin suppresses the secretion of FSH in humans.