Involvement of the renal kallikrein-kinin system in K⁺-induced diuresis and natriuresis in anesthetized rats

Intravenous infusion of a high-K⁺ solution (67.5 mM KCl, 67.5 mM NaCl) to anesthetized rats increased urine volume by 47.6% after 60 min, compared with infusion of a Na⁺ solution (135 mM NaCl). This treatment also increased urinary excretion of Na⁺ by 32.2%, in parallel with an increase in excretion of K⁺ or Cl^-. Urinary excretion of kallikrein increased within 60 min after the start of K⁺ infusion. A bradykinin B₂ receptor antagonist, 8-[3-[N-[(E)-3-(6-acetamidopyridin-3-yl)acryloylglycyl]-N-methylamino]-2,6-dichlorobenzyloxy]-2-methylquinoline (FR173657; 1.0 mg/kg, i.v.), inhibited the K⁺-induced diuresis and natriuresis by 41.0% and 26.7%, respectively. These results indicate that K⁺ load induces diuresis and natriuresis through the renal kallikrein-kinin system in rats. Copyright (C) 2000 Elsevier Science B.V.