过量蛋氨酸对大鼠肝、脑组织脂质过氧化作用的研究

A STUDY OF EXCESS METHIONINE ON LIPID PEROXIDATION OF LIVER AND BRAIN TISSUES IN RATS

本研究观察了过量蛋氨酸对大鼠脂质过氧化作用的影响。基本饲料为大米，添加小量黄豆，蛋白质水平１２％。大鼠随机分为对照组，２．０％蛋氨酸添加组，２．０％蛋氨酸和３．０％甘氨酸添加组。４周后实验结果表明，过量蛋氨酸使大鼠生长抑制，肝脏脂质过氧化物（ＬＰＯ）含量明显升高，超氧化物歧化酶（ＳＯＤ）活性显著降低。提示过量蛋氨酸的毒性可引起鼠肝脂质过氧化作用增强。添补甘氨酸能改善大鼠生长，但未能使鼠肝ＬＰＯ与ＳＯＤ恢复至对照组水平。反之，添加过量蛋氨酸，或添补过量蛋氨酸和甘氨酸，大鼠脑组织的ＬＰＯ与ＳＯＤ水平与对照组均无明显差异。说明过量蛋氨酸的毒性并未影响鼠脑的脂质过氧化作用．

he effect of excess methionine(Met)on lipid peroxidation of liver and brain was studied in rats,Thirty young male Wistar rats were random-ly divided into 3 groups of 10 each: rice-soybean basal diet with 0.2%DL-Met as control,2.0%DL-Met supplemented group,2.0%DL-Met and 3.0% glycine(Gly)supplemented group.All rats were fed ad libitum,The ani-mals were killed after 28 days.The results showe:1.The growth of ratswas depressed markedly when 2.0%DL-Met was fed. However,the grow-th retardation was alleviated obviously witl feeding Met and Gly diet.2.Hepatic LPO content was increased significantly, whereas its SOD activity reduced remarkably by 2.0%DL-Met supplementation, Similar results of high level of LPO and low of SOD were maintained by Met and Gly fed group.3.Compared with the control,addition of excess Met or ex-cess Met with Gly both did not affect the levels of LPO and SOD in rat brain,These observations suggested that there was a significant high lipid peroxidation in liver,but not in brain when excess Met was given.