Circulating concentrations of LH (mean ± sem) after bolus iv injections (arrows) of senktide (S) (50 μg), Kp-10 (K) (2 μg), and GnRH (G) (0.3 μg) given at 2-h intervals to agonadal juvenile male monkeys. Note that the order of treatment with the three peptides was different for each of the three animals (see experiment 4 under experimental design in Materials and Methods), and for presentation, the responses of two animals have been reordered to match those for the animal that received the sequence S, K, and G. n = 3.