Hataoka Kyoko, Kaizaki-Mitsumoto Asuka, Numazawa Satoshi
Division of Toxicology, Department of Pharmacology, Toxicology and Therapeutics, Showa University School of Pharmacy.
J Toxicol Sci. 2017;42(5):539-543. doi: 10.2131/jts.42.539.
A synthetic cathinone, 1-phenyl-2-(1-pyrrolidinyl)-1-pentanone (α-PVP), was occasionally found in the "bath salt" type of designer drugs, as an active ingredient. It has been reported that drivers who consumed α-PVP were in an excited state and incapable of controlling their behavior, causing traffic accidents. Despite its acute excitatory effects, there is no information on the psychological dependency elicited by α-PVP use. The purpose of the present study was to clarify whether the reward pathway is activated with repeated doses of α-PVP in experimental animals. Treatment of male C57BL/6j mice with α-PVP (25 mg/kg, i.p.), once a day, for 3 days significantly increased the conditioned place preference scores. Therefore, repeated doses of α-PVP were shown to induce palatability in mice. α-PVP increases extracellular dopamine levels in the nucleus accumbens shell immediately after administration. The number of cells immunopositive for phosphorylated cAMP-regulatory element binding protein (CREB) was significantly increased in the α-PVP-treated mice in our study. These results indicate that the administration of α-PVP activates the phosphorylation of CREB in the nucleus accumbens shell. Our results suggest that α-PVP stimulates the reward pathway by increasing the extracellular dopamine levels and CREB phosphorylation in the nucleus accumbens shell, eventually causing positive reinforcement in mice.
一种合成卡西酮,1-苯基-2-(1-吡咯烷基)-1-戊酮(α-PVP),偶尔会在“浴盐”类新型毒品中作为活性成分被发现。据报道,服用α-PVP的司机处于兴奋状态,无法控制自己的行为,从而引发交通事故。尽管其具有急性兴奋作用,但关于使用α-PVP所引发的心理依赖尚无相关信息。本研究的目的是阐明在实验动物中重复给予α-PVP是否会激活奖赏通路。对雄性C57BL/6j小鼠每天腹腔注射一次α-PVP(25毫克/千克),持续3天,显著提高了条件性位置偏爱得分。因此,重复给予α-PVP被证明可诱导小鼠产生愉悦感。给药后,α-PVP可立即增加伏隔核壳层细胞外多巴胺水平。在我们的研究中,α-PVP处理组小鼠中磷酸化环磷腺苷反应元件结合蛋白(CREB)免疫阳性细胞数量显著增加。这些结果表明,给予α-PVP可激活伏隔核壳层中CREB的磷酸化。我们的结果提示,α-PVP通过增加伏隔核壳层细胞外多巴胺水平和CREB磷酸化来刺激奖赏通路,最终在小鼠中产生正性强化作用。