Influence of dietary sodium on stimuli causing renin release

Abstract

Dietary sodium importantly influences release of renin stimulated by aortic constrictuon or infusion of norepinephrine. Dogs maintained on a low-sodium diet released renin more readily and in larger quantities in response to either stimulus than dogs on a standard kennel diet. In contrast with the correlation between renin release and dietary sodium, there was none between release of renin and the hemodynamic effects produced by norepinephrine. In dogs fed a regular diet, intravenous infusions of sodium nitroprusside caused release of renin when the initial rate of urinary sodium excretion was low and, conversely, failed to stimulate renin release when the initial rate of sodium excretion was high. In addition to the possibility that release of renin depends on the rate of tubular sodium re-absorption, it is proposed that sodium may act by conditioning sensitivity of response of the renin-releasing mechanism to change in transmural pressure at or near the afferent arteriole.