[The influence of the beta-blocking agent pindolol on blood pressure and heart weight of rats with Goldblatt-type hypertension (author's transl)].

Preexisting increase of plasma renin activity in hypertension seems to indicate an effective hypotensive action of adrenergic beta-receptor antagonists. In spite of marked elevation of plasma renin activity in Goldblatt-rats, the beta-blocker Pindolol failed to lower the blood pressure. On the contrary, high doses of this substance led to an acceleration of the Goldblatt-type hypertension, perhaps because of the intrinsic sympathomimetic activity of Pindolol. These findings support the conception that beta-blockers are effective in lowering the blood pressure only in hypertension with stimulated renin secretion, which is caused by an increased activity of the sympathetic nervous system. Plasma renin activity was not altered by Pindolol. There existed a linear relationship between blood pressure and left-ventricular weight in all groups of rats, which was not impaired by Pindolol in all used doses.