Gonadotropin response to acute administration of kisspeptin-10 to normal men (n = 6). A, Serum LH concentration in response to 1 μg/kg kisspeptin-10 (filled circles), 3 μg/kg kisspeptin-10 (filled triangles), or vehicle (open circles) administered to healthy volunteers at time 0. B, Δ AUC (60 min) of LH after kisspeptin-10 and vehicle administration. C, Δ AUC (60 min) of FSH after kisspeptin-10 and vehicle administration. Mean ± sem. *, P < 0.05 vs. vehicle.