Intrinsic cardiac neurons involved in cardiac regulation possess alpha 1-, alpha 2-, beta 1- and beta 2-adrenoceptors.

摘要: OBJECTIVE To determine whether intrinsic cardiac neurons involved in regulation possess alpha 1-, 2-, beta or 2-adrenoceptors. DESIGN The alpha1-adrenoceptor agonist phenylephrine, the 2-adrenoceptor clonidine, 1-adrenoceptor prenaterol and terbutaline were administered individually to a population of spontaneously active either locally (10 microL 100 microM solution; eight dogs) via local arterial blood supply (0.1 mL 20 artificially ventilated, open chest anesthetized dogs. Neuronal effects induced by each adrenergic agonists also tested presence an antagonist selective adrenoceptor subtype studied. MAIN RESULTS activity was modified at least one tested, 34% affected all four agonists. Alpha-adrenoceptor increased decreased neuronal activity, depending on On other hand, generated augmented beta-adrenoceptor Ventricular contractile force when excited spontaneous suppressed beta-adrenoceptor, but not alpha-adrenoceptor, blockade. cardiovascular responses no longer elicited its antagonist; they antagonists receptor subtypes CONCLUSIONS Intrinsic 1- receive tonic inputs beta-, alpha-, adrenoceptors. These data indicate that blockade may affect function, part, modification nervous system.