Calcitonin gene-related peptide: Enteric and cardiovascular effects in the dog

Abstract

We have measured the effects of intravenous infusion of calcitonin gene-related peptide at doses of 2.5, 10, and 50 pmol/kg · min on net jejunal water and solute fluxes and on plasma somatostatin concentrations in dogs. The hemodynamic effects and the pharmacokinetics of the peptide were also assessed. Using the triple-lumen perfusion technique in unsedated restrained animals it was shown that the highest dose of the peptide stimulated a transient net jejunal water and electrolyte secretion, and induced diarrhea in 4 of 6 animals receiving it. The peptide also induced dose-dependent tachycardia, hypotension, and increases in plasma immunoreactive somatostatin. All three doses of calcitonin generelated peptide produced plasma immunoreactive peptide levels within the elevated range previously measured in human patients with medullary thyroid carcinoma. Calcitonin gene-related peptide may have a major role in the pathogenesis of secretory diarrhea in medullary thyroid carcinoma.