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. ?-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

Objective To determine the effect of heroin on the gene expression of proliferating cell nuclear antigen(PCNA) in rat C6 glioma cells,and investigate the molecular mechanism of heroin addiction.Methods The rat C6 glioma cells were treated with heroin with doses of 0-100 mg?L-1 for 24 h,MTT assay was used to detect the viability of cells,the gene expression level of PCNA was determined by RT-PCR.Results When the C6 cells were treated with heroin with doses of 10,20 and 100 mg?L-1,the cell viabilities were 90.62%,80.97%,and 62.73%,there were significant differences compared with control group(P