title: Association between the A107V substitution in the δ-opioid receptors and ethanol drinking in mice selected for high and low analgesia.
abstract: Experimental evidence suggests that endogenous opioids play an important role in the development of ethanol addiction. In this study, we employed two mouse lines divergently bred for opioid-mediated stress-induced analgesia. In comparison with HA (high analgesia line) mice, LA (low analgesia line) mice, having lower opioid receptor system activity, manifest enhanced basal as well as stress-induced ethanol drinking. Here, we found that recently discovered C320T transition in exon 2 of the δ-opioid receptor gene (EU446125.1), which results in an A107V substitution (ACA23171.1), leads to higher ethanol preference in CT mice compared with CC homozygotes. This genetic association is particularly evident under chronic mild stress (CMS) conditions. The interaction between stress and ethanol intake was significantly stronger in HA than in LA mice. Ethanol almost completely attenuated the pro-depressive effect of CMS (assessed with the tail suspension test) in both the CC and CT genotypes in the HA line. In the LA mice, a lack of response to ethanol was observed in the CC genotype, whereas ethanol consumption strengthened depressive-like behaviours in CT individuals. Our results suggest that constitutively active A107V substitution in δ-opioid receptors may be involved in stress-enhanced vulnerability to ethanol abuse and in the risk of ethanol dependence.
authors.affiliation: Department of Molecular Cytogenetics, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Sacharczuk
authors.forename: Anna
authors.initials: A
authors.lastname: Lesniak
authors.forename: Andrzej W
authors.initials: AW
authors.lastname: Lipkowski
authors.forename: Michal
authors.initials: M
authors.lastname: Korostynski
authors.forename: Ryszard
authors.initials: R
authors.lastname: Przewlocki
authors.forename: Bogdan
authors.initials: B
authors.lastname: Sadowski
mesh_terms: D000428:Alcohol Drinking / Q000235:genetics*; D000437:Alcoholism / Q000235:genetics*; D000698:Analgesia; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D002492:Central Nervous System Depressants / Q000008:administration & dosage; D004195:Disease Models, Animal; D000431:Ethanol / Q000008:administration & dosage; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D018847:Opioid Peptides / Q000235:genetics* / Q000502:physiology; D011110:Polymorphism, Genetic / Q000235:genetics*; D017465:Receptors, Opioid, delta / Q000235:genetics*; D013315:Stress, Psychological / Q000503:physiopathology*
chemical_list: D002492:Central Nervous System Depressants; D018847:Opioid Peptides; D017465:Receptors, Opioid, delta; D000431:Ethanol
keywords: Ethanol drinking; selective breeding of mice; swim-stress induced analgesia; δ-opioid receptor polymorphism