不同浓度异氟醚对胎鼠海马区Caspase-3表达及血浆S100β水平的影响

Effects of different concentrations of isoflurane on the caspase-3 expression in the hippocampus and S100β level of plasma in fetal rats

目的 本研究探讨不同浓度的异氟醚对胎鼠海马区Caspase-3表达及血浆S100β水平的影响.方法 18只健康清洁级SD孕21 d大鼠随机数字表法分成对照组（C组）、1.3%异氟醚组（1.3% ISO组）、3%异氟醚组（3%ISO组）.C组不给予任何药物,1.3%ISO、3%ISO组分别吸入1.3%、3%异氟醚1 h,术中呼吸机控制呼吸,持续动态监测动脉血压,在模型建立完毕时（基础值）、30min后、1 h时抽取股动脉血检测血糖、血气.6h后3组孕鼠开腹随机取两只胎鼠,抽取胎鼠血液行S100β检测、通过免疫组化检测胎鼠海马CA1区Caspase-3阳性标记神经元的方法判断凋亡的情况.结果 与对照组胎鼠血浆S100β[（1.48±0.08）μg/L]比较,1.3%ISO组胎鼠[（1.53±0.12）μg/L]稍有升高,但两者间的差异无统计学意义,3%ISO组胎鼠[（3.12±0.15）μg/L,P＜0.05]明显升高,差异有统计学意义.与Con组胎鼠海马CA1区Caspase-3阳性标记的神经元数量比较[（33±4）个/mm2],1.3%ISO组胎鼠无明显改变[（31±5）爪/mm2],3%ISO组胎鼠明显增多[（75±7）个/mm2,P＜0.05],差异有统计学意义.结论 异氟醚对胎鼠脑发育的影响存在浓度依赖性,宫内暴露于3%异氟醚1h可诱发脑损伤,导致胎鼠血浆S100β浓度升高、诱发海马CA1区神经元发生凋亡;暴露于低浓度1.3%异氟醚1h不足以诱发脑损伤.

Objective To investigate the effects of different concentrations of isoflurane on the caspase-3 expression in the hippocampus and S100β level of plasma in fetal rats. Methods 18 pregnant rats at gestational day 21 were divided into control group, 1. 3% isoflurane group,3% isoflurane group. Rats in the control group spontaneously breathed 100% oxygen for 1 h. Rats in the treatment groups breathed 1.3% or 3% isoflurane in 100% oxygen through an endotracheal tube, with mechanical ventilation for 1 h. Rat pups were delivered by cesarean section 6 h after treatment, and fetal blood was sampled from the left ventricle of each fetal heart and evaluated for S100β. Fetal brains were then evaluated for apoptosis, using caspase-3 immunohistochemistry in the CA1 region of the hippocampus. Results Compared to the control group （（1. 48 ± 0. 08） μg/L） and the 1. 3% isoflurane group（ （1.53 ±0. 12）μg/L） ,the 3% isoflurane group showed significantly higher level of S100β（ （3. 12 ±0. 15） μg/L, P〈0.05） . There was no differences in densities of caspase-3-positive cells between the control （（33 ±4） cell/mm ） and 1.3% isoflurane groups（（31 ±5）cell/mm2）. Compared to 1.3% isoflurane,isoflurane at a concentration of 3%（（75 ± 7） cell/mm2, P〈0.05） for lh increased neurodegeneration in the hippocampal CA1 area in the developing brain of fetal rats. Conclusion Isoflurane can dose-dependently induce brain damage. Isoflurane at a concentration of 3% for lh can induce apoptosis in the hippocampal CA1 area and increase S100β levels of fetal rats.