中文摘要：

为探讨NO和巯基在山羊内毒素血症发病机理中的作用,将48只山羊随机分为对照组、内毒素组、褪黑素保护组、褪黑素组。每组12只,分别在处理后3、6 h各宰杀6只提取心肌线粒体,检测心肌线粒体中的MDA的含量,总巯基（T-SH）的含量,蛋白巯基（PB-SH）的含量,非蛋白巯基（NP-SH）的含量,以及总一氧化氮合成酶（TNOS）,分型一氧化氮合成酶（i NOS）的活性和一氧化氮（NO）水平的变化。结果显示,内毒素血症时山羊心肌线粒体中总巯基（T-SH）的含量,蛋白巯基（PB-SH）的含量,非蛋白巯基（NP-SH）的含量降低,MDA的含量,总一氧化氮合成酶（TNOS）,分型一氧化氮合成酶（i NOS）的活性和一氧化氮（NO）水平升高。而褪黑素治疗组则情况明显好转。结果表明,由于NO过量生成而引起的脂质过氧化损伤在山羊内毒素血症发病机理中起着重要的作用,褪黑素可有效拮抗脂质过氧化造成的损伤。

英文摘要：

To explore the role of NO and sulfhydryl on pathogenesis of endotoxemia in goats,48 goats were divided randomly into 4 groups of A,B,C and D with 12 goats in each group.Group A was normal control;Group B was LPS group;Group C was LPS＋MT group;Group D was MT group.each of which is divided into 3 h slaughter group after the injection of LPS and 6 h group after injection of LPS.the changes of the content of MDA,total sulfhydryl（T-SH）,protein SH（PB-SH） and non-protein SH（NP-SH） and the activity of nitric oxide synthase（T NOS）,inducible Nitric oxide synthase（i NOS） and nitric oxide（NO） level in myocardial mitochondria were detected.The results showed that when the goat developed endotoxemia the content of total sulfhydryl（T-SH）,protein SH（PB-SH）,non-protein SH（NP-SH） in myocardial mitochondrial decreased,the content of MDA and the activity of nitric oxide synthase（T NOS）,inducible nitric oxide synthase（i NOS） and nitric oxide（NO） level in myocardial mitochondrial significantly increased.Compared with the Lps group the situation of melatonin treatment group was significantly improved.The results indicated that,lipid peroxidation damage in the goat caused by the over-produced NO played an important role in the pathogenesis of endotoxemia.Melatonin can effectivly antagonize lipid peroxidation damage.