CO_2气压在颈部腔镜手术中对脑组织ET、nNOS影响的实验研究

Effect on Endothelin and Neuron Nitricoxide Synthase in Brain Tissue During Endoscopic Neck Surgery with Carbon Dixide Insufflation

目的:探讨在颈部腔镜手术中CO2压力对兔脑组织内皮素(ET)、神经型一氧化氮合成酶(nNOS)的影响并讨论其对脑组织损伤的意义。方法:运用CO2气建立和维持兔颈部的手术空间,24只动物分成4组,每组6只,即3个气压组(4mmHg、8mmHg、12mmHg)和1个对照组(0mm-Hg)。维持CO2气压150min后,对兔脑组织进行ET、nNOS免疫组化染色并结合计算机图像分析系统对表达变化进行评定。结果:各CO2气压组与对照组相比脑组织ET、nNOS阳性表达的平均光度、平均灰度有显著性差异(P<0.05)。12mmHg气压组脑组织ET与其他气压组有显著性差异(P<0.05),并出现脑组织水肿;12mmHg气压组、8mmHg气压组脑组织nNOS与对照组、4mmHg气压组有显著性差异(P<0.05),同时出现脑组织电镜下结构改变。结论:在颈部腔镜手术中,随着CO2气压增高及手术时间的延长,脑组织ET、nNOS增加,造成脑缺血和脑组织损伤。

Objective :To study the effect on Endothelin(ET) and Neuron nitri-coxide synthase(nNOS) in brain tissue during endoscopic neck surgerywith carbon dixide insufflation and to investigate the possible roles ofbrain damage in rabbits model .Method :Twenty-four rabbits ,6 pergroup, underwent endoscopic neck surgery .Insufflation was performedwith CO2at 4 mmHg ,8 mmHg ,12 mmHg and 0 mmHg(sham) . After150 min , we use i mmunohistochemicalacid to dyeing ET and nNOS ofrabbit cerebral tissue and use computer i mage analysis systemto assesstheir expression .Results :Every air pressure group compared with com-parison group:the average luminosity and average gray degree of ETandnNOS expressionin cerebral tissue are significance(P<0 .05) .12 mm Hgair pressure group compared with other groups :the expression of ETincerebral tissueis significance(P<0 .05)and cerebral tissue appears edema.12 mmHg air pressure group, 8 mmHg air pressure group comparedwith comparison group and 4 mmHg air pressure group separately : theexpression of nNOS in cerebral tissue is also significance(P<0 .05)andthe change of cerebral tissue structure in electron microscope appears .Conclusion:The study shows that :to raise carbon dioxide pressure andprolong surgical ti me canlead ETand nNOSincreasingin cerebral tissue ,and then cause cerebral ischemia and cerebral tissue damage .