Effects of brain natriuretic peptide and C-type natriuretic peptide infusion on urine flow and jejunal absorption in anesthetized dogs.

Effects of brain natriuretic peptide (BNP) or C-type natriuretic peptide (CNP) on urinary excretion and jejunal absorption of fluid and electrolytes were examined in anesthetized dogs. Intravenous infusion of BNP increased urinary fluid and electrolyte excretion and decreased jejunal fluid and electrolyte absorption. CNP had a similar effect on jejunal absorption as BNP. However, CNP had no significant effect on renal fluid or electrolyte excretion. These results indicate that: 1) BNP is a powerful natriuretic peptide comparable to ANP and; 2) CNP may also contribute to the regulation of body fluid homeostasis by way of inhibiting net jejunal fluid and electrolyte absorption.