Bradykinin (BK) enhances diuresis and natriuresis in saline volume-expanded dogs

15 micrograms bradykinin was given with large amount of physiological saline solution intravenously to dogs. Significantly greater diuresis and natriuresis were obtained compared with those of simple saline volume expansion experiments. Bradykinin in small doses which were selected as giving no influence on blood pressure enhanced additively diuresis and natriuresis, similarly with subpressor doses of A II, AVP, and MX in saline volume expanded dogs. Since all four agents are having cellular Ca-mobilizing action in common, it is suggested that phosphoinositide system may be involved in this enhancement of renal sodium and water excretion.