CONCENTRATIONS OF LUTEINIZING HORMONE IN THE SERUM OF MALE MICE AFTER SHORT-TERM AGGRESSIVE INTERACTION

Adult male mice were castrated and implanted with silicone elastomer capsules containing either testosterone or sesame oil. Brief exposure to a strange male opponent depressed levels of LH in castrated animals treated with oil, but did not add to the suppressive effects of testosterone on the concentration of LH in serum. Accessory organ weights were not affected by brief aggressive encounters, nor were levels of testosterone in serum altered in response to repeated encounters with a submissive (olfactory bulbectomized) male opponent. The observation that exposure to a strange male conspecific suppressed secretion of gonadotrophin in the absence of gonadal androgen(s) suggests that stress-responsive, antigonadotrophic factors can inhibit pituitary-gonadal function. A mechanism whereby gonadotrophin secretion may be suppressed in the androgen-deprived state is discussed.