Time dependence of frequency potentiation in the isolated guinea-pig's atrium.
D000818:Animals; D001794:Blood Pressure; D004558:Electric Stimulation; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006325:Heart Atria; D006339:Heart Rate; D008297:Male; D008722:Methods; D009638:Norepinephrine / Q000494:pharmacology; D010477:Perfusion; D013997:Time Factors
D009638:Norepinephrine