title: Antagonism between norepinephrine and the Ca++ channel blockers nifedipine and verapamil in isolated guinea pig ventricle.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004336:Drug Antagonism; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D009543:Nifedipine / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology*
chemical_list: D014700:Verapamil; D009543:Nifedipine; D009638:Norepinephrine