INVOLUTION OF THE ADRENAL CORTEX OF RATS TREATED WITH THIOURACIL

Abstract

Treatment of both immature and mature female rats with 0.1% thiouracil in the drinking water for a period of 6 weeks or longer resulted in an atrophy of the adrenal cortex. This change was also apparent when the adrenal wts. were expressed as a percentage of body wt. and thus could not be due to loss in body wt. It was concluded that the drug not only inhibited the growth of the adrenals but caused definite involution. Exposure of thiouracil treated rats to a temp. of 3[degree] [plus or minus] 1[degree]C showed a decrease in the ability of these animals to withstand cold. Within single age groups of thiouracil-treated rats a definite relationship was found to exist between the size of the adrenal cortex and the resistance to cold. Among the normal untreated rats this relationship was found only in the 5-weeks-old-group. No hypertrophy of the adrenal cortex occurred in the thiouracil treated rats after exposure to cold.