Reserpine-induced supersensitivity to the inotropic and phosphorylase activating effects of glucagon in the perfused rat heart.
Glucagon (0.125--2.0 microgram) produced a dose-dependent increase in cyclic AMP, % phosphorylase a and force of contraction in the isolated perfused rat heart. Pretreatment of animals with reserpine (2.5 mg/kg, 24 h) resulted in an enhancement of the inotropic and phosphorylase activating effects of glucagon but the effect on cyclic AMP was not altered. It is suggested that reserpine-induced supersensitivity in the rat heart occurs at a point beyond the cyclic AMP step.
D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D004347:Drug Interactions; D005260:Female; D005934:Glucagon / Q000494:pharmacology*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000201:enzymology* / Q000378:metabolism; D006005:Phosphorylases / Q000378:metabolism*; D051381:Rats; D012110:Reserpine / Q000494:pharmacology*; D013997:Time Factors
D012110:Reserpine; D005934:Glucagon; D000242:Cyclic AMP; D006005:Phosphorylases