Peculiarities of adrenergic regulation of smooth muscles in rabbit pulmonary arteries.
Muscle tension recording was used to study adrenergic contractile reactions of pulmonary artery smooth muscles in rabbits. Stimulation of alpha-adrenoceptors induced contraction of pulmonary artery smooth muscle cells. Endothelium partially inhibited the contractile effect of alpha-adrenoceptor agonists. Activation of smooth muscle beta-adrenoceptors in pulmonary arteries produced a dual dose-dependent effect (relaxation at agonist concentrations of 10 nM-1 muM and contraction at concentrations above 10 muM). The contractile effect of beta-adrenoceptor activation in smooth muscle cells is a specific feature of pulmonary arteries probably related to peculiarities of cAMP-signaling in these cells.
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D004837:Epinephrine / Q000494:pharmacology; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D011651:Pulmonary Artery / Q000502:physiology*; D011817:Rabbits; D011941:Receptors, Adrenergic / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D011941:Receptors, Adrenergic; D007545:Isoproterenol; D004837:Epinephrine