Effects of isoflurane on neuronal apoptosis In aged rats

Objective To investigate the effects of different concentrations of isoflurane on neuronal apoptosis in hippocampus and cerebral cortex in the aged rats. Methods Ninety female pathogen-free SD rats 22-24 months old weighing 497-593 g were randomly divided into 3 groups: group Ⅰ oxygen group inhaled air enriched with 40% O2,groupⅡ and Ⅲ were anesthetized with 1.2% and 1.8% isoflurane for 3 h respectively. Morris water maze was used to assess the cognitive function. The animals were killed at 24 and 72 h and on the 7th day after emergence from anesthesia and their brains were removed. Neuronal apoptosis in hippocampus and cerebral cortex was detected by TUNEL. Results The average escape latency was significantly longer on the 2nd and 3rd day after isoflurane anesthesia in isoflurane group than in oxygen group (P < 0.05 ). The neuronal apoptesis rate was significantly higher in the 2 isoflurane group than in oxygen group (P < 0.05 or 0.01 ). Conclusion Isoflurane anesthesia can result in transient cognitive dysfunction, and the mechanism may be involved in apoptosis in cerebral cortex in the aged rats. Key words: Isoflurane;  Aged;  Cognition disorders;  Neurons;  Apoptosis