title: [Effect of ATP and adenosine on the spontaneous electrical and contractile activity of portal vein smooth muscle cells].
abstract: It was shown in experiments on smooth muscle cells of the guinea-pig, rat and rabbit portal vein that adenosine (AD) and ATP exert both excitatory and inhibitory effects. The former effect is manifested by depolarization of the cell membrane, an increase in the frequency of action potentials (AP) and phasic contractions, as well as by the appearance of tonic contractions. The latter effect is accompanied by the inhibition of spontaneous activity and relaxation of a smooth muscle strip. It is suggested that the effects of ATP and AD are mediated by specific inhibitory and excitatory chemoreceptors in the muscle cell membrane, the former receptors being related to potential-dependent ionic channels, while the latter ones to potential-independent chemosensitive ionic channels. Apamine, a powerful blocker of non-adrenergic inhibition in the gastrointestinal tract, produces no influence on ATP and AD effects induced in smooth muscle cells of the portal vein.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000241:Adenosine / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D011169:Portal Vein; D011817:Rabbits; D051381:Rats; D013045:Species Specificity
chemical_list: D000255:Adenosine Triphosphate; D000241:Adenosine
vernacular_title: Vliianie ATF i adenozina na spontannuiu élektricheskuiu i sokratitel'nuiu aktivnost' gladkomyshechnykh kletok vorotnoĭ veny.