Effects of isoflurane anesthesia on cognitive function and expression of TSPO in brain tissues of aged rats

Objective To evaluate the effects of isoflurane anesthesia on the cognitive function and expression of translocator protein 18 kDa(TSPO)in the brain tissues of aged rats. Methods Twelve pathogen-free male Sprage-Dawley rats, aged 20 months, weighing 500-550 g, were randomly divided into 2 groups(n=6 each)using a random number table: control group(group C)and isoflurane anesthesia group(group I). The rats inhaled 2% isoflurane in 100% O2 for 4 h in group I, or 100% O2 for 4 h in group C. The rats underwent Morris water maze test at 24 h after anethesia.The escape latency and frequency of crossing the original platform were recorded.Then the rats were sacrificed, and the hippocampus and cerebral cortex were isolated for determination of the expression of TSPO and Iba1 by Western blot and quantitative real-time reverse transcriptase-polymerase chain reaction. Results Compared with group C, the escape latency was significantly prolonged, the frequency of crossing the original platform was decreased, and the expression of TSPO and Iba1 protein and mRNA in the hippocampus and cerebral cortex was up-regulated in group I(P<0.05). Conclusion Isoflurane anesthesia results in decreased cognitive function through up-regulating the expression of TSPO in the brain tissues of aged rats. Key words: Isoflurane; Aged; Cognition disorders; Membrane transport proteins; Brain