吗啡对大鼠嘌呤核苷酸分解代谢的促进作用及其可能的作用机制

目的　研究吗啡对嘌呤核苷酸分解代谢的影响及作用机制。方法　剂量递增腹腔注射吗啡 ,建立吗啡依赖大鼠模型。用试剂盒检测血浆尿酸含量、血浆及小肠组织黄嘌呤氧化酶 (XO)的活性。提取小肠组织总RNA ,采用逆转录聚合酶链反应检测小肠组织XOmRNA的水平 ,以β actinmR NA为内标。结果　动物血浆尿酸水平 ,3d和 7d吗啡用药组显示高于对照组 (P <0 0 5,n =10 ) ;3d、7d吗啡用药组动物血浆XO活性高于对照组 (P <0 0 5,n =10 ) ,在自然戒断 2组动物血浆XO活性也高于对照组 (P <0 0 1,n =10 ) ;3或 7d吗啡用药组动物小肠XO活性高于对照组 (P <0 0 5,n =10 ) ;7d吗啡用药组动物小肠XOmRNA表达水平高于对照组 (P <0 0 1,n =3 )。结论　吗啡促进嘌呤核苷酸分解代谢 ;其作用机制可能与吗啡提高大鼠小肠嘌呤核苷酸分解代谢关键酶XO的活性 ,增强其表达有关

Promotion of morphine on rat purine nucleotides catabolism and its possible mechanisms

AIMTo investigate the effect of morp hine on purine nucleotides catabolism and its possible mechanisms. METHO DSRats were administered with morphine by intraperitoneal injection with increasing dose to develop ad diction model. The determination of uric acid concentration in plasma and the ac tivities of xanthine oxidase (XO) in the plasma and the small intestine were per formed. RT-PCR was used to examine the expressing level of key enzyme of purine nucleotides catabolism,XO mRNA. β-actin was used as control gene in RT-PCR s tudy. RESULTSThe concentration of uric acid in plasma was sign ificantly increased in morphine-pretreated rats compared with control(P<0.0 5,n=10).The activity of XO in plasma of morphine-pretreated or natural with drawal rats was increased compared with the control(P<0 05,n=10).The a ctivity of XO in the small intestine of morphine-pretreated rats was extremely higher than that of control group (P<0 05,n=10).The level of transcrip t of XO mRNA was much higher in the id morphine-pretreated animals than that in the control group(P<0 01, n=3). CONCLUSIONMorphine promo tes the purine nucleotides catabolism,the mechanism of which might be related to the increases in the activity and expression level of the key enzyme XO of pur ine nucleotides catabolism in the small intestine.