Effects of adrenaline on isolated heart of the eel (Anguilla anguilla L.) during winter.
1. The intrinsic effects of adrenaline on the myocardium of the eel in winter were investigated in the isolated perfused eel heart. 2. Adrenaline was ineffective both on the pacemaker activity and auricular action potentials but markedly increased ventricular action potential duration, thus leading to an auriculo-ventricular desynchronisation. 3. This effect was not reversed by propranolol but was by phentolamine and was attributed to the stimulation of alpha receptors. 4. Clonidine reproduced the effect of adrenaline but also decreased the cardiac rhythm, possibly via alpha 2 adrenoceptors. 5. No direct inotropic effect was observed.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D004524:Eels; D004837:Epinephrine / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D012621:Seasons; D013599:Systole / Q000187:drug effects
D011433:Propranolol; D003000:Clonidine; D004837:Epinephrine; D010646:Phentolamine