Alcohol-induced alterations in phosphoinositide hydrolysis in astrocytes.
Cultured astrocytes exposed to ethanol were prelabeled with [3H]inositol and the accumulation of [3H]inositol phosphates was determined following stimulation with norepinephrine (NE). Acute doses of alcohol (25-200 mM) had little effect on phosphoinositide (PI) hydrolysis. However, chronic exposure for 7 days produced significant increases in hydrolysis with ethanol concentrations as low as 50 mM. The onset of alcohol-induced increases occurred within 4 hr of exposure, reaching maximum values by Days 3 to 5. Withdrawal resulted in the return of stimulated PI hydrolysis to pre-alcohol exposure levels after 2 days. The evidence provided suggests that chronic exposure of ethanol alters the alpha-adrenergic receptor characteristics of astrocytes and/or enhances the effector pathway leading to PI hydrolysis at a site distal to the receptor.
Ritchie
T
T
Alcohol Research Center, University of California, Los Angeles 90024-1759.
Kim
H S
HS
Cole
R
R
deVellis
J
J
Noble
E P
EP
D000818:Animals; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D001921:Brain / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D006868:Hydrolysis; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats
D010716:Phosphatidylinositols; D000431:Ethanol