title: Increase of electrocardiogram voltage and contractile force of the frog's heart induced by chloroquine.
abstract: The increase in the amplitude of the E.C.G. and ventricular contractile force induced by chloroquine sulphate was studied in frogs. It was shown that changes originated in the midbrain and were mediated through the sympathetic nervous system. The transmitter was recognized as a beta-adrenergic agent. The possible mechanism of action of chloroquine on the CNS responsible for the phenomenon observed was discussed.
mesh_terms: D000818:Animals; D001001:Anura; D001921:Brain / Q000502:physiology; D002738:Chloroquine / Q000494:pharmacology*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D013116:Spinal Cord / Q000502:physiology; D013268:Stimulation, Chemical; D013564:Sympathetic Nervous System / Q000502:physiology; D013997:Time Factors; D014628:Vagotomy
chemical_list: D002738:Chloroquine