Physiologic and Anatomic Effects of Propylthiouracil on Normal and Hypertensive Rats

The antithyroid drug propylthiouracil prevented or removed the hypertension associated with bilateral kidney encapsulation with latex envelopes. This effect did not appear to be the result of hypofunction of the adrenal glands. Propylthiouracil reduced growth rate in young rats and caused weight loss in adult rats. The latter effect appeared to be true tissue loss because water contents of heart, kidney, testes, liver, psoas, aorta and adrenal were unaffected. Administration of propylthiouracil for 7 to 19 weeks tended to reduce heart weight to body weight ratio as well as the ratio of kidney weight to body weight in both control and "encapsulated" rats. However, ratios of organ weight to body weight in the cases of thyroid, testes and eyes were larger than those of untreated control rats. In addition to its antihypertensive effect, propylthiouracil treatment of encapsulated rats also prevented the appearance of certain other manifestations of hypertension usually accompanying kidney encapsulation.