[Effect of acetylcholine on the heart ventricle of the goldfish Carassius auratus, Teleosts, Cyprinidae. Modification of the response as a function of temperature].
Acetylcholine (Ach) is more efficient on the red fish heart at 14 degrees C than at 5 degrees C or 8 degrees C. It does not probably exist a cholinesterasic system and high concentrations of Ach are to be used to obtain significant variations of the heart frequency. Ach does not appear as a physiological mediator and temperature seems to be an essential factor in heart regulation and modulation of the pharmacological effects of eventual mediators. A thermal adaptation exists but the fast increase of the temperature, in the presence of Ach, results in heart blocage, whose contractions reappear spontanously during cooling. This is at the present time no valuable hypothesis could be made to explain this phenomenon.
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D006054:Goldfish; D006339:Heart Rate / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects; D006801:Humans; D009200:Myocardial Contraction / Q000187:drug effects*; D013696:Temperature; D016276:Ventricular Function
D000109:Acetylcholine
Activité de l'acétylcholine sur le ventricule du coeur de poisson rouge Carassius auratus, Téléostéen, Cyprinidé. Modification de la réponse en fonction de la température.