Isoproterenol, norepinephrine and phosphodiesterase inhibitors are blockers of the depressed fast Na+-system in ventricular muscle fibers.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000502:physiology; D000242:Cyclic AMP / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D008274:Magnesium / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology*; D010210:Papillary Muscles / Q000187:drug effects*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D012964:Sodium / Q000502:physiology*
D010726:Phosphodiesterase Inhibitors; D012964:Sodium; D000242:Cyclic AMP; D008274:Magnesium; D007545:Isoproterenol; D002118:Calcium; D009638:Norepinephrine