Isoprenaline-like effects of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine on mechanical, biochemical and electrophysiological parameters in the mammalian heart.
The phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) mimicked the effects of isoprenaline on the force of contraction, the cAMP content and the slow Ca++ inward current (Isi) in isolated guinea pig papillary muscles. The results support the hypothesis that phosphodiesterase inhibitors and beta-adrenoceptor agonists exert their positive inotropic effects by increasing Isi via the common mediator cAMP.
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Brückner
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Gramann
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Nose
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Schmitz
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Scholz
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology; D007545:Isoproterenol / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects; D013268:Stimulation, Chemical; D013806:Theophylline / Q000031:analogs & derivatives*
D007473:Ion Channels; D013806:Theophylline; D000242:Cyclic AMP; D006152:Cyclic GMP; D007545:Isoproterenol; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine