Alpha- and beta-adrenoceptors on cultured glial cells.
The action of alpha- and beta-adrenoceptor agonists and antagonists has been studied on the membrane potential of glial cells in cultured rat central nervous system. Noradrenaline and the alpha-agonist phenylephrine caused a depolarization which was reversibly blocked by the alpha-antagonist phentolamine. In contrast, the beta-agonist isoprenaline hyperpolarized the glial membrane. This hyperpolarization was not associated with measurable changes in membrane resistance and was antagonized by the beta-blocker atenolol. These results suggest that the glial depolarization is mediated by activation of alpha-receptors, whereas the hyperpolarization is due to stimulation of beta-receptors. The existence of alpha- and beta-adrenoceptors on glial cells is further supported by autoradiographic studies showing binding of noradrenaline and alpha- and beta-antagonists to astrocytes.
D000818:Animals; D000831:Animals, Newborn; D001262:Atenolol / Q000494:pharmacology; D001345:Autoradiography; D002478:Cells, Cultured; D005333:Fetus; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D009457:Neuroglia / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D010656:Phenylephrine; D001262:Atenolol; D007545:Isoproterenol; D009638:Norepinephrine