The influence of potassium administration and of potassium deprivation on plasma renin in normal and hypertensive subjects

Abstract

A B S T R A C T The effect of potassium administration and of dietary potassium deprivation on plasma renin activity and aldosterone excretion has been studied in 10 normal subjects and in 12 hypertensive patients maintained on a constant dietary regimen.Potassium administration reduced plasma renin activity in 18 of 28 studies of both normal and hypertensive subjects. Suppression of renin often occurred despite sodium diuresis induced by potassium administration. The renin suppression was related to induced changes in plasma potassium concentration and urinary potassium excretion.The failure of suppression of plasma renin in 10 studies could be accounted for by the smaller amounts of potassium administered to these subjects, together with a possibly overriding influence of an induced sodium diuresis.In six studies potassium deprivation invariably increased plasma renin activity even though a tendency for sodium retention often accompanied this procedure.The data indicate that both the suppression of plasma renin activity induced by potassium administration and the stimulation of renin activity which follows potassium depletion occur independently of associated changes in either aldosterone secretion or in sodium balance. However, the results do suggest that in various situations, the influence of potassium on plasma renin activity may be either amplified or preempted by changes in sodium balance.These interactions between potassium and plasma renin could be mediated by an ill-defined extrarenal pathway. But the findings are more consistent with an

Effect of Sodium Restriction and Angiotensin II Infusion in Bartter's Syndrome

“…The only persistent abnormality which could be plasma aldosterone was observed. observed in our patients was hypokalemia, which is known to Blood sodium and potassium remained unchanged during A I1 induce high PRA levels (6,26). Therefore, we strongly support the infusion.…”

Relation of plasma renin to end organ damage and to protection of K+ feeding in stroke-prone hypertensive rats.

“…Such mechanisms include changes in extracellular fluid volume, 7 activation of central or autonomic nervous system, 8 " 10 enhanced vascular reactivity to pressor agents, 11 Previous research from our laboratory has defined the effects of dietary potassium deprivation and administration on plasma renin activity (PRA) in both animals 18 and human subjects. 19 We also detected a positive correlation between PRA and the development of stroke and heart attack in humans. 20 Furthermore, the activity of the renin system has been implicated in vascular injury, including stroke, in a variety of clinical and experimental situations.…”

Stimulation of renin secretion by potassium-channel activation with cromakalim

“…Mechanisms which are known to activate the secretion of renin in humans include an acute fall in BP, salt depletion, enhanced sympathetic discharge [23], and potassium retention [24]. BP and indices of the electrolyte-fluid volume state here were unchanged and, therefore, could not account for the renin-angiotensin stimulation by cromakalim.…”