[Action of noradrenaline and dopamine on the pacemaker cells of the normal rat sinus node and in pharmacological sympathectomy].
The authors studied the action of the physiological concentrations of catecholamines on the major parameters of the action potentials of the true pacemakers, using a graphic analysis of their electric activity at the intracellular microelectrode lead. Desympathization was carried out with the help of daily intraperitoneal injections of guanethidine solution for six weeks. Noradrenaline and dopamine have a similar effect on the electrogenesis of the pacemakers by decreasing a relative threshold of auto-stimulation and decreasing the steepness of the potential growth in phase 4 on the curve of the action potential. Pharmacological desympathization leads to the development of hyper-reactivity of the true pacemakers to noradrenaline and dopamine and triggers off changes in the regulation of the electric activity of these cells by catecholamines.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D003864:Depression, Chemical; D004298:Dopamine / Q000494:pharmacology*; D004594:Electrophysiology; D006145:Guanethidine; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012849:Sinoatrial Node / Q000166:cytology / Q000187:drug effects*; D013563:Sympathectomy, Chemical
D004298:Dopamine; D009638:Norepinephrine; D006145:Guanethidine
Deĭstvie noradrenalina i dofamina na kletki-voditeli ritma sinusnogo uzla serdtsa krys--v norme i v usloviiakh farmakologicheskoĭ desimpatizatsii.