The anxiolytic effect of acute ethanol or diazepam exposure is unaltered in mu-opioid receptor knockout mice.
Previous researchers demonstrate an opioidergic involvement in the anxiolytic and rewarding actions of ethanol and diazepam. Therefore, to further characterize the role of the opioid system in the anxiolytic action of ethanol and diazepam, normal (C57BL/6J), hybrid (B6129F1) and mu-opioid receptor knockout mice were given i.p. ethanol (0, 1.0 or 1.6 g/kg) or diazepam (1.5 mg/kg). The anxiolytic properties of these agents were then tested in the elevated plus-maze. Additional ethanol-treated mu-opioid receptor knockout mice (1 g/kg) were pretreated with the kappa-opioid receptor antagonist nor-BNI (0 or 3 mg/kg) to assess the involvement of kappa-opioid activity in ethanol's anxiolytic actions. The anxiolytic action of ethanol and diazepam in the mu-opioid receptor knockout mouse did not differ from the effects obtained in normal mice and pretreatment with nor-BNI did not significantly attenuate ethanol's actions in mu-opioid receptor knockout mice. Thus, the anxiolytic actions of ethanol and diazepam appear to be independent of opioid system activity in the mu-opioid receptor knockout mouse.
LaBuda
C J
CJ
Department of Psychology, University of Texas at Arlington, Arlington, TX 76019, USA. cjlabuda@yahoo.com
Fuchs
P N
PN
D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003975:Diazepam / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL / Q000235:genetics / Q000378:metabolism; D018345:Mice, Knockout; D009020:Morphine / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018847:Opioid Peptides / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D010147:Pain Measurement / Q000187:drug effects; D010641:Phenotype; D017450:Receptors, Opioid, mu / Q000172:deficiency* / Q000187:drug effects / Q000235:genetics
D014151:Anti-Anxiety Agents; D018847:Opioid Peptides; D017450:Receptors, Opioid, mu; D000431:Ethanol; D009020:Morphine; D003975:Diazepam