Effects of adrenalectomy with hormone replacement therapy on the presence of a sexual maturation-delaying chemosignal in the urine of grouped female mice.

When grouped, adult female mice excrete in their urine a chemosignal that delays sexual maturation of young females. This effect does not occur if the adult females have been adrenalectomized. In this report we test whether hormone replacement therapy affects the production and/or excretion of this chemosignal in adrenalectomized females. Injections of two glucocorticoids, corticosterone and hydrocortisone acetate, restored the delay chemosignal in excreted urine from grouped females. In subsequent dose-response experiments, we determined that daily injections of at least 125 micrograms corticosterone or 80 micrograms hydrocortisone acetate were needed to bring about the reappearance of the maturation-delaying substance in the urine of grouped adrenalectomized females. Injections of varying doses of a mineralcorticoid, deoxycorticosterone, did not produce restoration of the delay chemosignal in excreted urine from grouped females. Two additional tests revealed that injections of either glucocorticoid would restore the puberty-delaying activity to the bladder urine of both grouped and singly caged adrenalectomized females.