title: Dissociation of cyclic GMP from the negative inotropic action of carbachol in guinea pig atria.
abstract: The relationship between the negative inotropic action of carbachol and its ability to elevate cyclic GMP was determined in isolated paced guinea pig atria. A clear dissociation was observed between that concentration of carbachol which depressed contractility and that which elevated tissue cyclic GMP content. Doses as low as 0.03 micronM caused a negative inotropic effect while cyclic GMP was not elevated until concentrations nearly 100-fold higher were used. Thus a correlation between tissue cyclic GMP content and the negative inotropic action of carbachol was not found to exist in guinea pig atria.
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism*
chemical_list: D002217:Carbachol; D000242:Cyclic AMP; D006152:Cyclic GMP