异氟醚和七氟醚对新生大鼠脑皮质Caspase-3及微管相关蛋白1B表达的影响

目的 研究同等剂量的异氟醚和七氟醚对新生SD大鼠第一躯体感觉皮质(Primary Somatosensory cortex,SI)Caspase-3表达以及皮质微管相关蛋白1B(microtubule associated protein 1B,MAP1B)表达的不同影响.方法 出生后7d(P7)的新生SD大鼠5窝,每窝取11只,随机均分为异氟醚组(I组),七氟醚组(S组)和对照组(C组).各组分别吸入1.1%异氟醚或1.8%七氟醚或空气4h,在麻醉结束后2h每窝各取1只幼鼠灌注取脑,免疫组织化学法检测皮质SI区Caspase-3表达;另外,C组在麻醉处理0h,I组和S组分别在麻醉2h,4h每窝各取1只幼鼠取新鲜脑皮质,Western Blot检测MAPIB表达量的变化.结果 I组和S组SI区Caspase-3表达分别较对照组增加561.23%(t=4.45,P<0.01)和194.46%(t=5.17,P<0.001).I组比s组增加124.45%(P<0.05);I组皮质MAPIB在麻醉2h和4h分别较对照组增加了557.15%(t=16.54 P<0.01)和475.21%(t=32.97,P<0.01),MAPlB表达量2h与4h相比无统计学差异(P>0.05);S组皮质MAP1B在麻醉2h和4h分别较对照组增加了693.11%(t=9.45,P<0.01)和268.15%(t=2.79,P=0.049),4 h组表达量较2h降低了53.65%(P<0.01).结论 0.5MAC异氟醚比七氟醚诱导更多新生大鼠大脑皮质神经细胞表达Caspase-3,两者均可诱导幼鼠上调大脑皮质MAP1B的表达来启动机体自我修复功能.

Abstract：

Objective To investigate the effects of isoflurane and sevoflurane at the same dose on expression of Caspase-3 of primary somatosensory cortex (SI) and expression of micmmbule associated protein 1B (MAP1B)in cortical neuronsin neonatal SD rats.Methods Fifty-five neonatal SD rats at postnatal day 7 (eleven rats each litter,altogether 5 litters)were assigned randomly into control group(C group),isoflurane group (I group)and sevoflursne group(S group)in average.The rats in I group,S group or C group were exposed to 1.1% isoflurane or 1.8% sevoflurane (equivalent to 0.5MAC)or air 4h.The brain of neonatal rats were perfused and embedded by paraffin,Caspase-3 positive expression in the SI cortex of brain was detected by immunohistochemistry staining.Besides,the fresh cortex was dissected at O h in C group and at 2h,4h in I group and S group,microtubule associated protein 1 B expression was detected by West blot staining.Results Caspase-3 positive cells in the SI cortex were increased by 561.23%in I group(t=4.45,P<0.01)and 194.46% in S group(t=5.17,P<0.01)when compared with C group,and increased by 124.45% in I group(P<0.05)when compared with S group.The MAP1B protein was increased by 557.15%at 2h(t=16.54 P<0.01)and 475.21% at 4h(t=32.97,P<0.01)in I group while increased by 693.11%at 2h(t=9.45,P<0.001)and 268.15% at 4h(t=2.79,P=0.049) in S group when compared with C group.In S group,MAP1B protein at 4h reduced by 53.65%(P<0.01) when compared with that at 2h.Conclusion 0.5 MAC isoflurane can induce more apoptosis in the cortex in the neonatal rats'brain at postnatal day 7 than sevoflurane.They can both significantly promote the expression of MAP1B in the cortex to start the self-reparation.