ABSTRACT
Objective To investigate the effects of exogenous nitric oxide (NO) on gaseous transmitter molecule of the hippocampus in rats with global cerebral ischemic-reperfusion(I-R) injury.Methods Twenty-four Wistar male rates were randomly divided into 4 groups of sham operation (group S),I-R control(group I-R),I-R plus sodium nitroproside(SNP) 2 mg/kg(LSNP) or plus SNP 4 mg/kg(group HSNP) with 6 rats each.Global cerebral I-R model was established by 4-vessel occlusion.SNP was injected at 30 min before clamping the bilateral carotid arteries in groups of LSNP and HSNP.The carotid arteries were clasped for 20 min.The rats were killed after cerebral reperfusion for 6 h.The concentrations of hydrogen sulfide(H_2S),NO and CO,the activity of cystathionine beta synthase(CBS),HO and inducible nitric oxide synthase(iNOS),as well as the expression levels of CBS mRNA,iNOS mRNA and hemeoxygenase-1 (HO-1) mRNA in the hippocampus were measured.Results Compared to group S,the concentrations of H_2S,NO and CO,the activities of CBS,HO and iNOS and the expressions of CBS mRNA,iNOS mRNA and HO-1 mRNA in group I-R were increased(P<0.05 or P<0.01) ,which were all higher in groups of LSNP and HSNP than those in group I-R(P<0.05 or P<0.01).Conclusion Exogenous NO can induce the expressions of CBS mRNA and HO-1 mRNA,activate CBS and HO in rats with global cerebral I-R injury,indicating that NO has a modulation effect on the CBS/ H_2S and iNOS/NO systemes.