Effects of reactive oxygenspecies on cellular apoptosis induced by isoflurane in the forebrain of mice

：Objective By observingthe changes of Caspase-3 protein and reactive oxygen species (ROS) in the forebrain ofmice induced by isoflurane inhalation to study the role of ROS in neural damages ofisoflurane. Methods Fifty-six male C57BL/6Jmice were randomly divided into isofluranegroup(Iso, n=20), dimethylthiourea group(DMTU,n=8), imethylthiourea plus isofluranegroup(DMTU+lso, n=8), and control group(Con,n=20). Mice in Iso and DMTU+Iso groups wereexposed to three segments of 1.4%isoflurane, 2 h for each segment. Thirty min beforeoxygen inhalation in DMTU group and first segment of isoflurane inhalation in DMTU+Isogroup, 50 mg/kg of radical scavenger DMTU were intraperitoneally injected to the mice inthe two groups. The changes of caspase-3 expression in prefrontal cortex were observed byimmunocytochemical staining. And the activities of superoxide dismutase (SOD) and theamount of MDA were detected. Results Compared with Con group, the number of caspase-3positive cells in Iso group increased significantly (3.38 times, P＜0.05);but in DMTU+Iso group( 1.43 times of Con group) and DMTU group(0.74 times of Con group),itdid not change obviously (P＞0.05). There was nosignificant difference in the activities of SOD between Iso group [(25±10) U/mgprot] andCon group [(20±6) U/mgprot](P＞0.05), but lipid peroxidationmalondialdehyde (MDA) content in Iso group [(13.7±6.1 ) nmol/mgprot] was significantlyhigher than that in Con group [(5.7±2.7) nmol/mgprot](P＜0.05). Conclusion 1.4% isoflurane exposure significantlyincrease the expression of caspase-3 in the forebrain of mice and its molecular mechanismmay be related to the increase of free radicals. Key words: Isoflurane;  Caspase-3;  ROS;  SOD;  MDA