The effect of nitric oxide on expression of isoflurane preconditioning against brain ischemia-reperfusion

Objective To investigate the effect of isoflurane preconditioning on Bcl-2 and Bax mRNA expression and the signaling pathway of nitric oxide against brain ischemia-reperfusion(I/R).Methods Seventy-five male gerbils were randomly divided into 5 groups(n=15):SHAM,I/R,ISO,AG+ISO and AG group.Global cerebral I/R was produced by occlusion of bilateral common carotid arteries for 5 minutes and confirmed by isoelectric potential on EEG.In ISO group,the animals inhaled 1.2%-1.5% isoflurane for 30 minutes followed by 30 minutes wash-out period before I/R.In AG+ISO group,30 minutes after aminoguanidine,200 mg/kg i.p.isoflurane was inhaled as ISO group,and aminoguanidine was injected 30 min before I/R in AG group.After 24 hours,the forebrains were collected,and the expression of Bcl-2 and Bax mRNA was determined by reverse transcriptase polymerase chain reaction.Results Bcl-2 mRNA expression in ISO group(1.22±0.12) was significantly higher than that in sham(0.83±0.16),I/R(0.83±0.11) and AG+ISO group(0.82±0.12)(P<0.05).Bax mRNA expression in I/R and AG group was significantly higher than that in sham group(P<0.05),and the expression in ISO group was higher than that in AG+ISO group.Conclusion Nitric oxide is involved in the signaling pathway of isoflurane preconditioning and has the protection effect on gerbil brain against I/R. Key words: Nitric oxide; Isoflurane/PD; Reperfusion injury; Brain ischemia; Gene expression