Effect of ketamine on UCP 2 expression after cerebral ischemia-reprfusion in rats / 中华急诊医学杂志

ABSTRACT

Objective To investigate the effect of ketamine on hippocampal uncoupling protein 2 (UCP 2) expression after forebrain ischemia-reperfusion (I/R) in rats and the mechanism of protective effect of ketamine on brain. Method Forty-five male Wistar rats weighing 250～300 g were randomly divided into 3 groups, with 15 animals in each group. Forebrain I/R was estabhshed by occlusion of bilaleral carotid artery combined with hy-potemion,EFG in a sustained low rate of 7 Hz, 30～40 μVθ rhythm was the success signs of forebrain I/R. Con-trol group (C)sham operation was performed; I/R group (Ⅰ) bilateral common carotid arteries were clamped for lOmin combined with hypotension [MAP(40±5) mmHg] induced by exsanguinations, then saline (1 mg/kg) was injected into the lateral cerebral ventricle using microsyringe; ketamine group (K)ketamine (1 mg/kg) was injected into the lateral cerebral ventricle using microsyringe after I/R. The animals were decapitated, the brain was immediately removed,and the hippocampal tissues were dissociated at 6 h after reperfusion. The cerebral I/R injury was observed with light microscope, the levels of UCP 2 mRNA expression in hippocampus were detected by using semi-quantitative RT-PCR technique (n=7), coronal sections including hippocampal tissue were obtained for detection of UCP 2 protein expression by immuno-histochemistry (IH) method (n=8). The RT-PCRR and IH data were expressed as the mean±SD, the statistical signiticance was determined by one-way ANOVA. Results The UCP 2 mRNA expression was (1.06±0.02) in group Ⅰ and (1.18±0.06)in group K increased significantly compared with that in group C(0.91±0.02) (P<0.05), there were more UCP2 mRNA expression in group K increased than that in group Ⅰ(P<0.05). The expression of UCP 2 protein was (31.56±4.01) in group Ⅰ and (44.61±4.96) in group K, increased significantly compared with that in group C (17.91±5.49) (P<0.05),there were more UCP 2 protein expression in group K than that in group Ⅰ (P<0.05). Conclusions Ketamine can attenuate the cerebral I/R injury in rats, the underlying mechanism may be related to the up-regulartion of the expression of hippocampal UCP 2 mRNA and UCP 2 protein.