Naloxone reversal of stress-induced reproductive effects in the male rhesus monkey.
Adolescent male rhesus monkeys, stressed by placement in tethering systems, were administered naloxone to discern the involvement of endogenous opioids in the stress-induced reproductive dysfunction. Stressed monkeys exhibited decreased plasma levels of luteinizing hormone (LH), testosterone, and increased levels of prolactin. Administration of naloxone temporarily returned hormone levels to non-stressed values. Stress depressed sexual activity was increased following naloxone treatment. GnRH administration stimulated plasma LH and testosterone levels. These results indicate that stress-induced changes in reproductive function may be mediated by opioids at levels above the pituitary.
D000818:Animals; D004723:Endorphins / Q000502:physiology*; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D007986:Luteinizing Hormone / Q000097:blood; D008253:Macaca mulatta; D008297:Male; D010906:Pituitary Hormone-Releasing Hormones; D011388:Prolactin / Q000097:blood; D012735:Sexual Dysfunction, Physiological / Q000503:physiopathology*; D013312:Stress, Physiological / Q000150:complications* / Q000503:physiopathology; D013739:Testosterone / Q000097:blood
D004723:Endorphins; D010906:Pituitary Hormone-Releasing Hormones; D013739:Testosterone; D011388:Prolactin; D007986:Luteinizing Hormone