Relationship of human urinary and plasma kinins to sodium-retaining steroids and plasma renin activity.

In these studies we have shown that: 1. urinary kallikrein is an index of sodium-retaining steroid activity and may participate in the anti-natriuretic and kaliuretic effects of these hormones; 2. urinary kinin excretion is independent of changes in urinary kallikrein excretion; 3. levels of plasma bradykinin are highly correlated with levels of plasma renin activity probably because both respond to changes in extracellular fluid volume; and, 4. plasma bradykinin may act to antagonize angiotensin II to maintain normal blood pressure in hyper-reninemic states.