Association between the A107V substitution in the delta-opioid receptors and ethanol drinking in mice selected for high and low analgesia

作者：Sacharczuk Mariusz^*; Lesniak Anna; Lipkowski Andrzej W; Korostynski Michal; Przewlocki Ryszard; Sadowski Bogdan

来源：Addiction Biology, 2014, 19(4): 643-651.

DOI：10.1111/adb.12030

• Ethanol drinking
• selective breeding of mice
• swim-stress induced analgesia
• delta-opioid receptor polymorphism

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 delta-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 delta-opioid receptors may be involved in stress-enhanced vulnerability to ethanol abuse and in the risk of ethanol dependence.

• 出版日期2014-7