Effects of β-blocking agents on blood pressure and plasma renin activity in experimental renovascular hypertension

• Published in: The Japanese Journal of Nephrology Vol. 19; no. 11; pp. 921 - 928
• Main Authors: Takata, Masanobu, Shimao, Masato, Uno, Denji, Arai, Shiro, Takabatake, Toshikazu, Nomura, Gakuji, Hattori, Nobu
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Nephrology 1977
• ISSN: 0385-2385; 1884-0728
• DOI: 10.14842/jpnjnephrol1959.19.921

This study was attempted to clarify the mechanism of antihypertensive effect of β-blockers. Constriction of one renal artery in the presense of the intact opposite kidney produced hyperten-sion and increased plasma renin activity in 38 male rabbits. Pindolol, 10mg/day, propranolol, 50mg/day, tiprenolol, 20 mg/day, or oxprenolol, 60 mg/day was administered orally for 17 days since the 8th day after clipping, and blood pressure and plasma renin activity were measured. The following results were obtained. 1) Each of the β-blockers was observed to reduce blood pressure on the 3 rd day after the administration, and it was sustained till the end of the experiment. 2) Under this experimental condition, the antihypertensive effects of pindolol and tiprenolol were both found to be more potent than that of propranolol. 3) Each of the β-blockers was observed to tend to reduce plasma renin activity on the 3 rd day after the administration, and it was sustained till the end of the experiment. 4) The renin suppression of propranolol was immediate and lasting, while that of oxprenolol was delayed. The renin suppression of tiprenolol was immediate, but was weakened at the end of the experiment. The renin suppression of pindolol was more marked than oxprenolol but less marked than tiprenolol till the 10th day, and the weakest of the four drugs on the 17 th day. 5) No relation was found between renin suppression and antihypertensive effect. It suggests that the anti hypertensive mechanism of β-blockers has no relation to renin suppression.