Mechanisms of Desoxycorticosterone Action. XII: Influence of the Thyroid

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

The effect of the thyroid on the development of DCA hypertension was studied by comparing the behavior of DCA-treated thyro-parathyroidectomized rats with DCA-treated controls. Thyro-parathyroidectomy prior to implantation of a single 20-mg DCA pellet prevented hypertension and all tissue lesions except periarteritis nodosa, during a 15-week period in which the animals slowly matured. Subsequent administration of minimal doses of thyroxine (insufficient to restore the histological picture of the hypophysis completely to normal) was associated with the development of hypertension and cardiac hypertrophy, although the growth rate was not materially accelerated. It was concluded that the thyroid hormone may represent a significant factor in the development of DCA hypertension. The ability of DCA to induce periarteritis nodosa without hypertension in the thyro-parathyroidectomized rat suggests that this preparation may offer a new approach to studies of the pathogenesis of periarteritis.