alpha-Adrenergic receptor-mediated depolarization of rat neocortical astrocytes in primary culture.
The membrane potentials of rat neocortical astrocytes growing in primary cultures (mean resting potential; -79 mV at [K+]o = 4.5 mM) were depolarized by up to 30 mV by 10(-5) M norepinephrine added to the medium, or up to 11 mV by norepinephrine or phenylephrine applied by ionophoresis. This depolarization could be inhibited by the alpha-adrenergic receptor antagonist phentolamine (10(-5) M) but not by the beta-adrenergic antagonist propranolol (10(-5) M). These results suggest that the norepinephrine-evoked depolarizations seen in these cells may be mediated through an alpha-adrenergic receptor.
D000818:Animals; D001253:Astrocytes / Q000502:physiology*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000502:physiology*; D004347:Drug Interactions; D009638:Norepinephrine / Q000008:administration & dosage; D010646:Phentolamine / Q000008:administration & dosage; D010656:Phenylephrine / Q000008:administration & dosage; D011433:Propranolol / Q000008:administration & dosage; D051381:Rats; D011941:Receptors, Adrenergic / Q000502:physiology*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*
D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D010656:Phenylephrine; D011433:Propranolol; D009638:Norepinephrine; D010646:Phentolamine