Serum FSH and LH in male mice following aggressive and nonaggressive interaction

Previously isolated, adult, male mice were maintained for four days either in continued isolation or as pairs which were either separated from each other or not by a wire mesh barrier. Males without the barrier in place were categorized as dominant or subordinate on the basis of wounding. In general, fighting resulted in decreased concentrations of circulating FSH and LH, as well as the expected increase in adrenal weight and decrease in weight of the seminal vesicles. Such changes were decidedly more exaggerated in subordinates than among dominant males. Body weight was not affected by any of the experimental treatments. Pituitary content of the gonadotropins also remained relatively unchanged except for a significant depression in LH among dominant males.