title: Effects of taurine depletion on rat cardiac electrophysiology: in vivo and in vitro studies.
abstract: Electrocardiograms were monitored in unanesthetized rats during treatment with drinking water containing guanidinoethyl sulfonate (GES), an inhibitor of taurine transport, which depleted cardiac taurine content. Treatment led to a selective prolongation of the QT interval which was highly correlated with the degree of taurine depletion (r2 = 0.92, p less than .001). Compared to controls, the duration of ventricular muscle action potentials was significantly increased in GES-treated rats, and this accounted for the prolongation of QT intervals. Oral taurine supplements reversed GES-induced cardiac taurine depletion and the associated increased duration of action potentials and QT intervals. In vitro superfusion with 0.2-10 mM GES or taurine had no effect on action potentials of control or GES-treated rats. These data indicate that intracellular taurine may play a role in regulating myocardial action potential duration, particularly during repolarization.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000502:physiology; D004247:DNA / Q000032:analysis; D004562:Electrocardiography; D006321:Heart / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009206:Myocardium / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013654:Taurine / Q000031:analogs & derivatives / Q000032:analysis / Q000494:pharmacology / Q000502:physiology*; D013997:Time Factors
chemical_list: D013654:Taurine; C009558:taurocyamine; D004247:DNA; D002118:Calcium