Effects of chronic ethanol treatment and ethanol withdrawal on [3H]SCH23390 binding to rat striatal membranes.
The effects of chronic ethanol administration and ethanol withdrawal on the kinetic and pharmacological properties of [3H]SCH23390 binding sites and the labelling of central dopamine D-1 receptors were studied in the striatum of the rat. Chronic 40 day ethanol treatment produced a statistically significant decrease (p < 0.05) in maximum binding (Bmax) on striatal dopamine D-1 receptors of the rat, KD remaining unaltered. The withdrawal of ethanol did not affect the kinetic binding parameters. The rank order of potency in displacing the specific [3H]SCH23390 binding of several dopamine antagonists, agonists and serotonin-related drugs was consistent with the pharmacological profile of dopamine D-1 receptors. Chronic ethanol treatment led to a statistically significant increase in receptor affinity (lower Ki than controls) for (+)-butaclamol (p < 0.05). Ethanol withdrawal for 24 hr increased the affinity of [3H]SCH23390-labeled binding sites for norepinephrine. The addition of 0.03-0.68 M ethanol in vitro had no significant effects on [3H]SCH23390 binding in striatal preparations taken from both control and ethanol-treated rats. The results show that rat striatal [3H]SCH23390-labelled binding sites are affected by different conditions of ethanol exposure, possibly suggesting the medication of striatal dopamine pathways in the responses to ethanol intoxication.
Gili-Martín
E
E
Department of Fundamental Biology, University of Vigo, Spain.
Fernández-Briera
A
A
Calvo
P
P
D000818:Animals; D001552:Benzazepines / Q000378:metabolism*; D002492:Central Nervous System Depressants / Q000378:metabolism / Q000633:toxicity*; D015259:Dopamine Agents / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism / Q000633:toxicity*; D017072:Neostriatum / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D018490:Serotonin Agents / Q000378:metabolism; D013375:Substance Withdrawal Syndrome / Q000378:metabolism*
D001552:Benzazepines; D002492:Central Nervous System Depressants; D015259:Dopamine Agents; D017447:Receptors, Dopamine D1; D018490:Serotonin Agents; D000431:Ethanol