过量蛋氨酸对大鼠肝、脑组织脂质过氧化作用的研究

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．

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

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.