围麻醉期三碘甲状腺原氨酸改善新生鼠七氟烷麻醉所致的远期行为学异常

Supplementation with triiodothryonine perianesthesia improves sevoflurane-induced long-term behavior disorders

目的 观察新生鼠七氟烷（SEV）麻醉对成年后认知功能的影响以及三碘甲腺原氨酸（T3）对其干预作用.方法 选取7日龄（P7） SD大鼠65只,随机分为3组：生理盐水组（NS组）、SEV组（注射NS）及T3组.每天注射1次,间隔24 h,连续3d.麻醉后6h各组随机取3只幼鼠计算海马区原位缺口末端标记法（TUNEL）阳性细胞密度.余饲养至P30行行为学测试.随后尼氏法检测海马区神经元的密度.结果 麻醉后6h,SEV组较NS组和T3组TUNEL阳性细胞密度均显著增加（n=3,P＜0.05）.P30～ P33,SEV组较NS组和T3组逃避潜伏期显著延长[NS组：（26.35±16.06）s,SEV组：（44.70±14.95）s,T3组：（31.43±10.68）s,n=13,P＜0.05].P36时,NS组及T3组海马CA3区神经元的密度明显高于SEV组[NS组：（24.88±1.65）/mm2,SEV组：（13.93±0.88）/mm2,T3组：（25.00±1.81）/mm2,n=4,P＜0.01],NS组与T3组组间比较差异无统计学意义（P＞0.05）.结论 T3可减弱新生鼠七氟烷麻醉后远期的行为学异常,可能和减少海马区细胞凋亡有关.

Objective To observe the effects of supplementation with triiodothryonine perianesthesia on sevoflurane-induced cell apoptosis and long-term behavior disorders.Methods Sixty-five postnatal day 7 （P7） SD rats were randomly divided into three groups.The rats were exposed for 4 h to either 2％ sevoflurane combined with intraperitoneal injection physiological saline （NS,SEV group） or triiodothryonine 100 μg/kg （T3 group） or exposed for oxygen 1 L/min combined with NS as a placebo （NS group）.The treatments were given once every 24 h for three days except inhalation processes.Six h after the end of anesthesia,3 rats were randomly selected from each group to assess cell apoptosis in the hippocampus.Then behavioral tests were implemented when P30-P36.Then their brains were prepared for Nissl-staining to study the cytoarchitecture of the hippocampus.Results The density of TdT-mediated dUTP nick end labeling （TUNEL） positive cells in DG and SVZ regions-of SEV group w.as_significantly higher than that in NS group and T3 group （n =3,P ＜ 0.01 and P ＜ 0.05,respectively）.At P30-33,the escape latency of SEV group was significantly longer than that in NS group and T3 group [NS group：（26.35±16.06） s,SEV group：（44.70±14.95） s,T3 group：（31.43±10.68） s,n=13,P＜0.05],but the data showed no significant difference between NS group and T3 group （P ＞ 0.05）.At P36,the density of neurons in CA3 of T3 group and NS group was higher than that of SEV group [NS group：（24.88 ± 1.65）/mm2,SEV group：（13.93 ±0.88）/mm2,T3 group：（25.00 ±1.81）/mm2,n=4,P＜ 0.01].But the data showed no significant difference between T3 group and NS group （P ＞0.05）.Conclusion Triiodothryonine can alleviate sevoflurane-induced behavior disorders in adulthood,which may be associated with reduced cell apoptosis in the hippocampus.