Competitive antagonism between norepinephrine and propranolol.
D000818:Animals; D004336:Drug Antagonism; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000502:physiology*; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D016276:Ventricular Function
D011433:Propranolol; D009638:Norepinephrine