复合致病因素诱导的肝硬化大鼠血浆同型半胱氨酸变化及其意义

Changes of plasma homocysteine and its significance in rats with hepatic cirrhosis induced by multiple pathogenic factors

目的探讨复合致病因素诱导的肝硬化大鼠血浆同型半胱氨酸变化及其意义。方法采用复合致病因素法制备大鼠肝硬化模型,正常对照组动物饲以标准饲料和自来水。分别在喂饮4,6,8周无菌无内毒素条件下取血测定血浆中谷丙转氨酶(alanine transferase,ALT)、同型半胱氨酸(homocysteine,Hcy)、叶酸、维生素B12(VitB12)、内毒素(endotoxin)、肿瘤坏死因子-α(tumor necrosis factorα,TNF-α)含量,取肝组织测定匀浆中一氧化氮(nitric oxide,NO)和丙二醛(malondialdehyde,MDA)含量以及抗O.2-活力。结果随肝硬化病程进展,血浆内毒素和Hcy逐渐升高并呈平行变化,8周时升高具有统计学意义(P<0.05);TNF-α从4周到8周逐渐升高,均显著高于正常对照(P<0.05);匀浆中NO在4周即显著升高,之后呈下降趋势,但在8周仍显著高于正常对照水平(P<0.05);抗O2.-活力在6周时升高显著(P<0.05);MDA呈明显增高趋势,至8周时显著高于正常对照与4周和6周时;各时间点叶酸和VitB12含量变化不大;相关分析显示,血浆内毒素与血浆TNF-α和Hcy、与匀浆NO和MDA之间呈显著相关,匀浆NO与Hcy和MDA之间显著相关。析因分析显示,甲硫氨酸循环中相关因素对总变异的贡献是:同型半胱氨酸>VitB12>叶酸。结论复合致病因素诱导肝硬化大鼠发生的高同型半胱氨酸血症,可能与肠源性内毒素血症互为因果,加重肝脏损伤,最终促进肝硬化形成。

Objective To investigate the changes of homocysteine in plasma and its significance in rats with hepatic cirrhosis induced by multiple pathogenic factors.Methods The rat hepatic cirrhosis model was established by employing multiple pathogenic factors.Rats in normal control group were fed with standard food and tap water.The alanine transferase（ALT）,homocysteine（Hcy）,folic acid,vitamin B12（VitB12）,endotoxin and tumor necrosis factor-α（TNF-α）in plasma,and nitric oxide（NO）,malondialdehyde（MDA）and the activity of anti-superoxide anion in hepatic homogenate were measured at week 4,week 6 and week 8 after feeding,respectively.Results With the progression of liver cirrhosis,both Hcy and endotoxin increased parallelly in model rats,and they significantly increased at week 8 compared with normal controls（P0.05）.TNF-α was evidently increased from week 4 to week 8,significantly higher than that in the normal controls（P0.05）.NO gradually deceased in model rats from week 4 to week 8,but it was significantly higher than that in the normal controls at every time point（P0.05）.The activity of anti-superoxide anion peaked in model rats at week 6,and significantly higher than that in the controls（P0.05）.MDA gradually elevated in the development of cirrhosis,and was markedly higher at week 8 than that at week 4 and week 6（P0.05）.No significant changes were found in folic acid and VitB12.The plasma endotoxin was related to TNF-α and Hcy in the plasma,NO and MDA in the homogenate,and NO level in the homogenate was related to Hcy,MDA.Factorial analysis showed that the contribution of the total variance among methionine cycle-related factors was homocysteineVitB12folic acid.Conclusion The hyperhomocysteinemia（HHcy）exists in rats with liver cirrhosis induced by multiple pathogenic factors.Both HHcy and intestinal endotoxemia（IETM）are reciprocal causation in the pathogenesis of liver injury,which aggravate the hepatic primary damage and ultimately lead to the liver cirrhosis.