Influence of kallidin-10 on renal function

Abstract

The intrarenal infusion of kallidin-10 at 1–3 µg/min in the dog produces an increase in directly measured renal blood flow with no alteration in systemic blood pressure. Concomitant with the increase in blood flow, a diuresis is observed which is associated with substantial increases in sodium and chloride excretion but smaller increases in total solute and potassium excretion. Neither urinary pH nor free water changed consistently. The pattern of water and electrolyte secretion suggests that the observed changes are secondary to an increase in glomerular filtration rate, although an increase in endogenous creatinine or inulin clearance could not be detected. The contralateral kidney showed no changes during infusion of the decapeptide indicating the rapidity with which it is destroyed in vivo. The renal responses to acetylcholine mimic those produced by kallidin-10. These data, together with earlier observations showing that the kidney excretes both the proteinase, urinary kallikrein, and its hypotensive polypeptides, suggest that this enzyme system may contribute to renal blood flow regulation and to salt and water homeostasis.