Antagonism of the stimulant and depressant effects of ethanol in rats by naloxone.
The action of naloxone (0.5 and 2 mg/kg IP) on the behavioural effects of a low (2 g/kg PO) and a high dose (4 g/kg PO) of ethanol was studied in rats. Ethanol at the low dose increased spontaneous motility, enhancing open-field external ambulations and reducing shuttle-box latency. All these effects were antagonized by naloxone. Ethanol at the high dose produced by hypomotility, decreasing open-field external ambulations and impairing shuttle-box performance. In this case, naloxone also reduced the ethanol effect, but its action was less consistent. Therefore, although mechanisms other than a specific opioid receptor blockade by naloxone must be considered, an involvement of opioid peptides in the effects of ethanol cannot be discounted.
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D000431:Ethanol / Q000037:antagonists & inhibitors*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D009270:Naloxone; D000431:Ethanol