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 KCI, 67.5 mM NaCl) to a nesthetized rats increased urine volume by 47.6% after 60 min, compared wit h infusion of a Na+ solution (135 mM NaCl). This treatment also increased u rinary 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 afte r the start of K+ infusion. A bradykinin B-2 receptor antagonist, 8-[3-[N-[ (E)-3-(6-acetamidopyridin-3-yl)acryloylglycyl]-N-methylamino]-2,6-dichlorob enzyloxy]-2-methylquinoline (FR173657; 1.0 mg/kg, i.v.), inhibited the K+-i nduced diuresis and natriuresis by 41.0% and 26.7%, respectively. These res ults indicate that K+ load induces diuresis and natriuresis through the ren al kallikrein-kinin system in rats. (C) 2000 Elsevier Science B.V. All righ ts reserved.