CCK受体拮抗剂对吗啡戒断大鼠海马神经元CaMKⅡα mRNA及蛋白表达的影响

目的研究胆囊收缩素(CCK)受体拮抗剂对吗啡戒断大鼠海马神经元CaMKⅡαmRNA及蛋白表达的影响,进一步探讨CCK受体拮抗剂抑制吗啡戒断症状的作用机制。方法应用剂量递增法皮下注射盐酸吗啡,建立大鼠吗啡躯体依赖模型,将模型鼠的海马组织制成细胞悬液,体外给予不同剂量CCK-A及CCK-B受体拮抗剂,采用RT-PCR和western blot技术分别检测海马神经元CaMKⅡα的mRNA及蛋白表达。结果①慢性吗啡成瘾大鼠海马神经元CaMKⅡα mRNA及蛋白表达与对照组相比均显著增高;②成瘾大鼠海马神经元细胞在给予纳洛酮催促戒断后,与对照组及吗啡组相比,CaMKⅡα mRNA及蛋白均显著降低;③纳洛酮催促戒断组加入不同剂量的CCK-A受体拮抗剂(CR-1409)、CCK-B受体拮抗剂(CR-2945),CaMKⅡα mRNA及蛋白表达与纳洛酮组相比显著升高,并随浓度的升高而升高,两种拮抗剂的作用以CR-2945起主要作用。结论CCK-A、CCK-B受体拮抗剂可以有效地抑制因纳洛酮催促戒断所引起的CaMKⅡα mRNA及蛋白表达降低,并具有剂量依赖性。

Effect of CCK receptor antagonists on CaMKⅡα mRNA and protein of neuron in hippocampus of morphine withdrawal rats

Objective To study the effect of CCK receptor antagonists on expressions of the Ca2+/Calmodulin-Dependent Protein Kinase Ⅱ CaMKⅡα mRNA and protein of neuron in hippocampus of morphine withdrawal rats in order to explore mechanism of CCK receptor antagonists on inhibition morphine withdrawal symptom in rats.Methods The models of morphine physical dependent rats were established by subcutaneous injection of morphine in gradually increasing doses. Application of CCK-A and CCK-B receptor antagonists and naloxone in vitro after preparation cells suspension isolated from hippocampus of the models in chronic morphine administration rats. The expressions of Ca2+/Calmodulin-Dependent Protein Kinase Ⅱα mRNA and protein were assayed with methods of RT-PCR and western-blot.Results ①The expressions of the Ca2+/Calmodulin-Dependent KinaseIIα mRNA and protein level of neuron in hippocampus of chronic morphine treatment rats were significantly increased as compared with the control group. ②Comparing with the control and morphine groups, application of naloxone to neuron in hippocampus of chronic morphine treatmented rats resulted in the decrease of CaMK II at both mRNA and protein levels. ③The expressions of Ca2+/Calmodulin-Dependent KinaseIIα mRNA and protein level increased in a dose dependent manner by CCK-A receptor antagonists(CR-1409) and CCK-B receptor antagonists(CR-2945). CR-2945 had been shown to play an important role.Conclusion CCK-A and CCK-B receptor antagonists could enhanced the expressions of Ca2+/Calmodulin-dependent kinaseIIα mRNA and protein which could be decreased by naloxone in a dose dependent manner.