Zarrindast Mohammad-Reza, Nouri Maryam, Ahmadi Shamseddin
Department of Pharmacology and Iranian National Center for Addiction Studies, Medical Sciences, University of Tehran, Iran.
Brain Res. 2007 Aug 13;1163:130-7. doi: 10.1016/j.brainres.2007.06.015. Epub 2007 Jun 16.
Interactions between cannabinoid and opioid systems have been reported in many studies. In the present study, we have investigated influence of cannabinoid CB1 receptor mechanism on the acquisition of conditioned place preference (CPP) induced by morphine in male Wistar rats. The cannabinoid CB1 receptor agonist (WIN55,212-2) and antagonist (AM251) were injected bilaterally into the dorsal hippocampus. Morphine and naloxone were injected subcutaneously (s.c.). The conditioning treatments with injections of morphine (6 and 9 mg/kg) induced a CPP for the drug-associated place. When administered into the dorsal hippocampus, WIN55,212-2 (1 microg/rat) induced CPP, but significantly did not alter CPP induced by a sub-effective dose of morphine (3 mg/kg). Moreover, administration of different doses of AM251 (50 and 100 ng/rat) into the dorsal hippocampus induced CPP, while did not change CPP by the sub-effective dose of morphine. Naloxone alone (1 mg/kg) induced conditioned place aversion (CPA). The drug (0.5 and 1 mg/kg) also caused CPA when co-administered with WIN55,212-2 (1 microg/rat). These results suggest that endocannabinoid system in the dorsal hippocampus is important for the CPP paradigm. However, agents did not alter morphine-induced CPP.
许多研究报告了大麻素系统与阿片系统之间的相互作用。在本研究中，我们研究了大麻素CB1受体机制对雄性Wistar大鼠中吗啡诱导的条件性位置偏爱（CPP）获得的影响。将大麻素CB1受体激动剂（WIN55,212-2）和拮抗剂（AM251）双侧注射到背侧海马体中。吗啡和纳洛酮皮下注射。注射吗啡（6和9mg/kg）的条件处理诱导了对药物相关位置的CPP。当注入背侧海马体时，WIN55,212-2（1μg/大鼠）诱导了CPP，但显著未改变由次有效剂量吗啡（3mg/kg）诱导的CPP。此外，将不同剂量的AM251（50和100ng/大鼠）注入背侧海马体诱导了CPP，同时未改变次有效剂量吗啡诱导的CPP。单独使用纳洛酮（1mg/kg）诱导了条件性位置厌恶（CPA）。当与WIN55,212-2（1μg/大鼠）共同给药时，该药物（0.5和1mg/kg）也引起了CPA。这些结果表明，背侧海马体中的内源性大麻素系统对CPP范式很重要。然而，这些药物并未改变吗啡诱导的CPP。
