The effects of beta-sympathomimetic amines and phosphodiesterase inhibitors on electrophysiological parameters in Purkinje fibres.
Dose-dependent responses to L-isoprenaline of spontaneous activity and plateau height in Purkinje fibres can be mimicked closely by the PDE-inhibitor IBMX. Simultaneous applications of sympathomimetic amines and IBMX result in potentiated responses. The results support the hypothesis that cyclic-AMP is the common mediator of positive chronotropic and inotropic effects induced by beta-sympathomimetic amines.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D006329:Heart Conduction System / Q000502:physiology*; D007545:Isoproterenol / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D011690:Purkinje Fibers / Q000187:drug effects / Q000502:physiology*; D013806:Theophylline / Q000031:analogs & derivatives*
D013806:Theophylline; D007545:Isoproterenol; D015056:1-Methyl-3-isobutylxanthine