Lack of acute effect of triiodothyronine on noradrenaline responses of isolated sympathectomized cat hearts.
The effect of 3-5-3'-triiodothyronine (T3) on chronotropic and inotropic responses to noradrenaline (NA) was studied on isolated heart preparations of cats sympathectomized with 6-OH-dopamine. Heart rates, left ventricular isovolumic pressure (P) and dP/dt were recorded, and concentration dose-response curves to NA were constructed. In the test series, T3 (0.01 and 0.1 microng per ml) was added to the perfusion medium. T3 did not affect the form nor the position of these curves. The results indicate that T3 does not have an acute effect on NA responses of symtropic effects of its own in these experimental conditions.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D004298:Dopamine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006321:Heart / Q000187:drug effects* / Q000294:innervation; D006339:Heart Rate / Q000187:drug effects; D009638:Norepinephrine / Q000008:administration & dosage / Q000494:pharmacology*; D010477:Perfusion; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology; D014284:Triiodothyronine / Q000494:pharmacology*
D014284:Triiodothyronine; D004298:Dopamine; D009638:Norepinephrine