Effect of sevoflurane anesthesia on activation of gliocytes in aged rat hippocampi

Abstract

Objective To evaluate the effect of sevoflurane anesthesia on activation of gliocytes in aged rat hippocampi.Methods One hundred and four male Wistar rats,weighing 600-650 g,were randomly divided into 2 groups (n =52 each) using a random number table:control group (group C) and sevoflurane group (group S).Group S inhaled 3.6％ sevoflurane for 2 h,and open reduction and internal fixation was performed after tibial fracture was induced.Y-maze test and fear conditioning test were carried out on days 1,3 and 7 after surgery.Six rats of each group were chosen on days 1,3 and 7 after surgery and hippocampi were removed to detect the activation of microglias and astrocytes (by immunofluorescence) and expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) (by Western blot).Results Compared with group C,the number of entries into each arm was significantly reduced,the duration of N arm stay was shortened,the percentage of time spent freezing induced by condition and the percentage of time spent freezing induced by context were decreased,and the activation of microglias and astrocytes was increased,and the expression of IL-6 and TNF-α was up-regulated in S groups (P ＜ 0.05).Conclusion Sevoflurane-induced postoperative cognitive dysfunction may be related to enhanced activation of gliocytes in aged rat hippocampi. Key words: Anesthetics, inhalation; Microglia; Astrocytes; Aged; Hippocampus