Effects of sevoflurane on microglial polarization after traumatic brain injury in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of sevoflurane on microglial polarization after traumatic brain injury (TBI) in rats.Methods Seventy-two healthy adult male Sprague-Dawley rats,weighing 230-250 g,were divided into 3 groups (n=24 each) using a random number table method:sham operation group (group Sham),group TBI,and TBI plus sevoflurane anesthesia group (group TBI+Sevo).TBI models were established by using Feeney's method in TBI and TBI+Sevo groups,30 min later 2.4％sevoflurane was inhaled for 1 h once a day for 3 consecutive days in TBI+Sevo group,while pure oxygen was inhaled instead in Sham and TBI groups.At 1,3,7 and 14 days after establishing the model,6 rats were selected,the neurological function was evaluated with the modified neurologic severity score (mNSS),and tail venous blood samples were taken for determination of tumor necrosis factor-a (TNF-α),interleukin-1beta (IL-1β) and IL-6 concentrations by enzyme-linked immunosorbent assay.The rats were then sacrificed,the limbic cortical tissues of brain contusion lesion were taken for determination of cell apoptosis (by TUNEL) and expression of microglial marker lba-1,microglial M1 phenotypic marker CD86 and microglial M2 phenotypic marker CD206 (by Western blot).Results Compared with group Sham,the mNSS score,apoptosis rate of cortical cells,expression of Iba-1,CD86 and CD206,and concentrations of serum TNF-α,IL-1β and IL-6 were significantly increased in TBI and TBI+Sevo groups (P＜0.05).Compared with TBI group,the mNSS score,apoptosis rate of cortical cells,expression of Iba-1 and CD86 and concentrations of serum TNF-α,IL-1β and IL-6 were significantly decreased,and the expression of CD206 was up-regulated in TBI+Sevo group (P＜0.05).Conclusion The mechanism by which sevoflurane anesthesia reduces TBI may be related to promoting microglial polarization and inhibiting systemic inflammatory response in rats.