神经降压素对醋氨酚引起肝损伤的保护作用及其与谷胱甘肽系统的关系

CYTOPROTECTIVE EFFECT OF NEUROTENSIN ON ACETAMINOPHEN INDUCED LIVER INJURY IN RELATION TO GLUTATHIONE SYSTEM

本工作观察了神经降压素（ＮＴ）对醋氨酚引起的小鼠在体肝脏和高体肝细胞损伤的保护作用及其与各胱甘肽系统的关系。结果表明，ＮＴ在整体和离体肝细胞均能减轻醋氨酚诱导的转氨酶的漏出，且在离体肝细胞部分翻转了醋氨酚引起的ＤＮＡ合成速率的下降。在离体肝细胞醋氨酚使细胞内还原型谷胱甘肽（ＧＳＨ），谷胱甘肽总含量和谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性均降低，但氧化型谷胱甘肽（ＧＳＳＧ）含量无明显改变。ＮＴ预处理后再给予酪氨酚，则ＧＳＨ含量进一步下降，而ＧＳＳＧ、谷胱甘肽总含量及ＧＳＨ－ＰＸ活性均增加，提示ＮＴ一方面促进谷胱甘肽的合成，另一方面通过提高ＧＳＨ－Ｐｘ的活性，促进ＧＳＨ转变成ＧＳＳＧ，从而提高了肝细胞清除自由基的功能。

In the present work the cytoprotective effect of neurotensin(NT)on acetuminophen induced injury to the liver or cultured hepotocytes of mouse in relstion toglutathione system were investigated.The results were as follows:Pretreatment withNT significantly reduced the leakages of transaminases induced by acetuminophen in vivoor in cultured hepatocytes and partialy reversed the decline of DNA synthesis inducedby acetuminophen in cultured hepatocytes.After administration of acetuminophen tocultured hepatocytes,the contents of reduced glutathione (GSH)and total glutathionedecreased,the activity of glututhione peroxydase(GSH-Px)decreased,but the contentsof oxidized glutathione(GSSG)showed no change.Pretreatment with NT before acetuminophen decreased the contents of GSH further but increased the contents of GSSGand total glutathione and enhanced the activity of GSH-Px.These results indicated thatNT may enhance synthesis of glutathione and the ability for hepotocytes to scavengefree radicals by increasing the activity of GSH-Px accompanied by oxidation of GSH toGSSG.