Influence of the extracellular Ca ++  concentration on the positive chronotropic action of adrenaline in the isolated atria of newborn and adult guinea-pigs.
D000818:Animals; D016275:Atrial Function; D002118:Calcium / Q000378:metabolism*; D004562:Electrocardiography; D004837:Epinephrine / Q000378:metabolism* / Q000494:pharmacology; D005110:Extracellular Space / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006325:Heart Atria / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction
D002118:Calcium; D004837:Epinephrine