ADRENALECTOMY IN THE RAT

Abstract

In 185 bilaterally adrenalectomized rats from 5 colonies, 4 of the colonies gave practically identical results, a 95% mortality within 20.5 days, with an average life-span of 7 days; but animals from a 5th colony showed a marked survival difference[long dash]a 50% survival for 30 days or longer after adrenalectomy, with an average life-span of 14.4 days for those that died. The extent of these colony differences is sufficient to explain many previous diverse reports in the literature. The average life-span of animals under 2 mos. age from the 4 colonies in which there was a high mortality was 5.7 days, or 1.3 days less than the average for all of these animals classified together. Sex made no consistent difference in the life-span. The average life-span of [female][female] was one day less than that of [male][male] but a higher percentage of [female][female] than of [male][male] survived indefinitely. Previous reports that adrenalectomy in the rat is uniformly fatal only when certain tissues around the adrenal proper are removed along with the gland were not verified. Accessory cortical tissue, either in macro- or microscopic amounts, was generally found in those animals that lived over 1 mo. Adrenalectomized [female] rats, capable of bearing normal litters, rarely lactated in amounts adequate to raise their young in normal fashion if gross accessory cortical bodies were not present. No changes of probable consequence were observed in the tubules of the testes of rats dying of adrenal insufficiency.