Objective To measure the sevoflurane minimum alveolar concentration( MAC) and to investigate the effect of sevoflurane anesthesia on the expression of poly ( ADP-ribose ) polymerase-1 ( PARP-1 ) protein in various brain regions in 7-day postnatal mice. Methods One hundred neonatal Sprague-Dawley(SD) rats(7 days postnatal, P7) were selected in this study. The sevoflurane MAC was determined in littermates(aged 7 days, n=10) using tail-clamp stimulation in a bracketing study design. At the end of anesthesia with different concentration gradient and duration gradient of sevoflurane, arterial blood samples from left ventricular of 3 random rats of each anesthesia maintenance were obtained immediately for blood gas analysis, and choose the maximum concentration and duration to keep the normal respiratory parameters. Then the neonatal mice were randomly divided into three different groups:the control group( A) , the sham anesthesia group( B) , and the anesthesia group( C) , the expression contents of PARP-1 protein in different brain regions were tested by Western blotting 6 hours after exposure. Results The sevoflurane MAC of the 7 days mice was(2. 64±0. 12)%, 0. 8MAC and 4 h anesthesia was set as the most suitable concentration rate and the anesthesia duration, respectively. Compared to the group A(100%), the PARP-1 expression in the hippocampus(270±22)%, the cortex of the temporal lobe(160±15)%, and the cortex of the frontal lobe (165±8)% of the group C was significantly increased(P<0. 05), however, the PARP-1 expression in the thalamus(115±26)% was not statistically significant between the Goup A and C. The parameters of the Group B was not significantly different with Group A(P>0. 05). Conclusion The sevoflurane MAC of the 7 days mice was 2. 64%. 0. 8 MAC sevoflurane anesthesia for 4 h may induce neuron apoptosis in cortex and hippocampus of the 7-days mice brain, and especially in hippocampus area.%目的：本研究通过测定出生7 d幼鼠的七氟烷最低肺泡有效浓度( minimum alveolar concentration,MAC),同时观察七氟烷对幼鼠不同脑区多聚腺苷二磷酸核糖聚合酶-1[poly(ADP-ribose)polymerase-1,PARP-1]表达的影响,探讨七氟烷对发育神经元的毒性作用。方法选取出生后7 d、体质量15~20 g的Sprague-Dawley( SD)幼鼠,采用数字表法随机抽取10只幼鼠,利用多次刺激法和夹鼠尾法测定幼鼠的七氟烷MAC值。然后设定不同浓度梯度及时间梯度的七氟烷维持麻醉,每种麻醉处理方法随机选3只幼鼠,于麻醉结束后即刻行左心室取血进行血气分析,选择不影响呼吸参数的七氟烷最大浓度和最长维持时间作为麻醉处理条件。将幼鼠随机分为对照组( A组)、假麻醉组( B组)和麻醉组( C组),各组经不同处理后6 h,选取6只幼鼠用蛋白免疫印迹( Western blotting)方法检测不同脑区PARP-1蛋白表达。结果出生后7 d幼鼠的七氟烷MAC值为(2.64±0.12)%。根据血气分析结果,设定0.8MAC、4 h定为最佳处理条件。与A组(100%)比较,C组海马(270±22)%、颞叶皮质(160±15)%和额叶皮质(165±8)%PARP-1蛋白表达显著增加(P<0.05),丘脑组织(115±26)%差异无统计学意义(P>0.05)。结论出生7 d幼鼠的七氟烷MAC值为2.64%。0.8MAC浓度七氟烷作用于出生后7 d的幼鼠4 h,可诱发皮质脑区及海马组织神经元凋亡,且于海马组织最为显著。
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