Suppression of renal sympathetic activity with potassium supplement in DOCA-salt rats.

We studied the involvement of renal sympathetic nervous system activity in the antihypertensive and natriuretic effects of potassium supplement in DOCA-salt treated rats. Systolic blood pressure of DOCA-salt rats rose substantially, reaching 181 +/- 3 mmHg after 4 weeks of DOCA-salt administration. In contrast, the supplement of 1% KCl solution attenuated the development of the hypertension until the fourth week (120 +/- 1 mmHg). After the 4-week treatments, renal norepinephrine turnover rate was calculated from the decline in specific activity after the injection of dl-3H-norepinephrine. It was markedly accelerated in DOCA-salt rats as compared to control rats. In contrast, 1% KCl supplement significantly restored to normal the increased renal norepinephrine turnover rate in DOCA-salt rats. Taken together, evidence presented suggests that the normalization of the increased renal sympathetic tone may be involved in the natriuretic and antihypertensive effects of potassium supplement in DOCA-salt hypertensive rats.