微波照射预处理对兔肝内源性一氧化氮影响的实验研究

Effects of Preconditioning by Microwave Radiation on Liver Endogenous NO Changes in Rabbits

目的:观察微波照射对兔肝脏缺血再灌注损伤中的肝功能ALT、A ST、LDH、肝组织匀浆一氧化氮(NO)、一氧化氮合酶(NO S)的变化,并探讨其保护机制。方法:32只新西兰大白兔被随机分为A、B、C、D共4组。各组于术后2h、4 h抽血查ALT、A ST、LDH。实验结束处死获取肝脏标本,检测各组的NO、NO S并行HE染色。结果:B、C、D三组的ALT、A ST、LDH显著高于A组。而C、D组的NO、NO S显著低于A、B两组,其中D组又显著低于C组。C组病理改变明显轻于D组。结论:适宜条件的微波照射预处理能明显改善缺血再灌注损伤的肝功能,减轻肝细胞损伤,而NO是该保护机制中的一个重要因素。

Objective：To observe changes of liver function （ALT,AST,LDH） ,hepatic contents of NO,NOS after preconditioning with microwave-irradiation during hepatic ischemia -reperfusion （I/R） injury in rabbits and to explore its protective mechanism. Methods：Thirty-two rabbits were randomly divided into four groups：normal control group （group A） ,microwave radiation group （group B） ,preconditioning plus I/R group （group C）and I/R group （group D）. 2 or 4 hours after hepatic I/R injury, blood was obtained for assay of ALT,AST and LDH from all groups. At the end of experiment , animals were sacrificed and liver tissue samples were collected, Tissue homogenate （10%） was made for determination of hepatic contents of NO,NOS by nitrate reductase method. Liver tissue samples were stained by hematoxylin-eosin （HE） and for morphological changes of liver tissue. Results;At the same time point, serum values of ALT. AST. LDH from groups B,Cand D were higher than those from group A（P〈0. 01） ,respectively. Compared with group D, Values of ALT ,AST, LDH and in group C were all increased remarkably （P〈0.01）. There seemed no changes of live contents of NO,NOS between group A and group B （P〉0.05）, but there were marked differences between group A, B and group C,D （P〈0.01）. Compared with group C,hepatic contents of NO,NOS from D group were lower significantly （P〈0.01）. Pathological examination revealed that morphological changes in group C were attenuated apparently compared with group D. Conclusions ： Preconditioning with microwave radiationcould improve hepatic function and atten- uate hepatocellular damage in rabbit liver I/R injury,and could resulted in increased production of NO and NOS,which indicated that NO might be involved in the protection of preconditioning with microwave iradiation against I/R injury.