Expression of nitric oxide synthase during germ cell apoptosis in testis of cynomolgus monkey after testosterone and heat treatment.

This study investigates the possible involvement of nitric oxide synthase (NOS) in activating germ cell death in monkeys after mild testicular hyperthermia and/or hormonal deprivation. Groups of 8 adult male monkeys received 1 of the following treatments for 12 weeks: 1) 2 empty Silastic implants, 2) 2 testosterone (T) implants, 3) daily exposure of testes to heat (43 degrees C for 30 minutes) for 2 consecutive days, or 4) 2 T implants plus testicular heat exposure. Testicular biopsies were performed before and on days 3, 8, 28, and 84 of the treatment.