Administration of leu-enkephalin impairs the acquisition of preference for ethanol
The effects of subcutaneous administration of leu-enkephalin (LEU-E) (10, 100 and 300 micrograms/kg) and LEU-E (100 micrograms/kg) plus naloxone (2.5 mg/kg) on ethanol preference and fluid intake have been investigated in rats. Under our procedural conditions, rats develop ethanol preference through forced ethanol drinking (conditioning session). Preconditioning administration of LEU-E induced a reduction of later ethanol preference. Post-conditioning administration of LEU-E (10 and 100 micrograms/kg) also attenuated the development of ethanol preference. NX antagonized the effects of LEU-E on ethanol preference and fluid consumption in the two experimental procedures used, indicating an involvement of opioid receptors in the LEU-E-induced impairment of the acquisition of ethanol preference.
Keywords: Alcohol Drinking/ drug effects ; Animals ; Conditioning ; Operant/ drug effects ; Enkephalin ; Leucine/ pharmacology ; Ethanol/ pharmacology ; Male ; Naloxone/pharmacology ; Rats ; Rats ; Inbred Strains
Author address: Department of Psychobiology, Cajal Institute, Madrid, Spain.
Record created on 2007-01-18, modified on 2016-08-08