Pharmacological properties of the norepinephrine-induced depolarization of astrocytes in primary culture: evidence for the involvement of an alpha 1-adrenergic receptor.
The membrane potentials of astrocytes in primary cultures prepared from neonatal rat cerebral cortices were depolarized by (-)-norepinephrine. The average first response to 10(-5) M (-)-norepinephrine was 24 mV from an average resting potential of -68 mV, and the average for the second response was 14 mV. Thus this process showed marked desensitization. The response was attributed to an activation of an alpha 1-receptor since it was about 1000 times more sensitive to inhibition by prazosin than to yohimbine or idazoxan. In addition, depolarization was seen to the application of 10(-5) M phenylephrine.
Bowman
C L
CL
Division of Neurosurgery, Albany Medical College, NY 12208.
Kimelberg
H K
HK
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004146:Dioxanes / Q000494:pharmacology; D019329:Idazoxan; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology*; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D015016:Yohimbine / Q000494:pharmacology
D004146:Dioxanes; D011942:Receptors, Adrenergic, alpha; D015016:Yohimbine; D009638:Norepinephrine; D011224:Prazosin; D019329:Idazoxan