Chemical renal medullectomy: effect on blood pressure in normal rats.

The renal medulla may have a vasodepressor function in blood pressure control. We have studied the effect of selective ablation of the medulla produced with 2-bromoethylamine hydrobromide on blood pressure in the rat. Increasing doses of bromoethylamine produced a corresponding degree of histological damage. Five weeks after medullary ablation intra-arterial blood pressure was elevated only in those groups of animals which had confluent necrosis of the papilla. The degree of hypertension was not related to plasma renin concentration but showed a significant correlation with urinary prostaglandin E2 excretion. Hypertension in medullectomized animals is probably due to a loss of a medullary vasodepressor function.