Mechanisms of Desoxycorticosterone Action. XI. Influence of the Pituitary

¹ From the Research Division, Nepera Chemical Company, Yonkers, New York

The effects of a combination of DCA implantation and lyophilized whole pituitary (LWP) on the blood pressure, fluid exchange, growth, survival and tissue structure of hypophysectomized rats were compared with the effects of DCA and LWP alone, and of DCA in intact animals. The combination of DCA and LWP in hypophysectomized animals was followed by the development of hypertension and by the cardiac and renal hypertrophy associated with DCA hypertension in the nonhypophysectomized animal. These changes were milder in degree and were accompanied by little or no histological evidence of damage. The DCA-treated hypophysectomized animals which did not receive LWP developed neither hypertension nor cardiac and renal hypertrophy, although they did exhibit the increase in fluid exchange produced by DCA in intact animals. The results confirm the hypothesis that a factor or combination of factors present in the intact gland or in whole pituitary extract, but not present in single fractions previously tested, is an essential co-factor in the production of hypertension by DCA.