Selective Alteration of Secretin-Stimulated Cardiac Adenylate Cyclase Activity in Streptozotocin-Diabetic Rats

P. Chatelain; L. Gillet; M. Waelbroeck; J. C. Camus; P. Robberecht; J. Christophe

doi:10.1055/s-2007-1018808

Hormone and Metabolic Research, Table of Contents

Horm Metab Res 1983; 15(12): 620-622
DOI: 10.1055/s-2007-1018808

Selective Alteration of Secretin-Stimulated Cardiac Adenylate Cyclase Activity in Streptozotocin-Diabetic Rats

P. Chatelain¹ , L. Gillet, M. Waelbroeck, J. C. Camus, P. Robberecht, J. Christophe²

¹Continental Pharma Research Laboratories, Mont Saint-Guibert, Belgium
²Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Brussels, Belgium

Abstract

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Summary

Secretin stimulation of adenylate cyclase activity in heart membranes was selectively altered in streptozotocin-diabetic adult male rats suffering from moderately severe diabetes, 40 days after i.v. streptozotocin administration (40 mg/kg body weight). The efficacy of secretin was reduced by 55% whilst its potency was unaffected. By contrast, the stimulation of adenylate cyclase by NaF, GTP, Gpp(NH)p, D,L-isoproterenol, and glucagon remained normal. The present data, together with the markedly reduced secretin response of cardiac adenylate cyclase in genetically obese (fa/fa) Zucker rats might indicate that hypoinsulinemia and insulin resistance both reduce the number of secretin receptors coupled to the adenylate cyclase system, an alteration whose contribution to diabetic cardiomyopathy remains to be determined.

Key-Words:

Rat Heart - Adenylate Cyclase - Secretin - Streptozotocin - Diabetes - Hormone Receptor

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