氯化镉对大鼠肝线粒体和微粒体膜功能的影响

Effects of cadmium chloride on membrane functions of rat liver mitochondria and microsomes

体外观察ＣｄＣｌ２对大鼠肝线粒体和微粒体膜流动性，膜结合酶活性，脂质过氧化产物丙二醛（ＭＤＡ）生成的影响以及维生素Ｃ的拮抗作用。结果表明，Ｃｄ２＋可在较短时间内引起膜流动性的降低和ＭＤＡ的增高，并伴有膜结合酶活性的抑制；维生素Ｃ处理不能改善膜流动性的降低。但能完全拮抗ＭＤＡ的增高，并部分缓解Ｃｄ２＋对葡萄糖－６－磷酸酶的抑制，提示Ｃｄ２＋膜毒性并非单纯由脂质过氧化所致，其中包括了对膜脂双层的直接作用。

The effects of Cd2+ on rat hepaticmitochondrial and microsomal membrane fluidities.membrane-bound enzyme acdvides.malondidldehyde(MDA)and vitamin C antagonistic action were investi-gated.Tberesults show that the fluorescencepolarization of 1,6-diphenyl-1,3,5-hexatriene labeledon the membranes ofmitochondha and microsomes issignificantly increased. The activities of Ca2+ ATPase,G-6-PaseNADPH-cvtOchrome Cfcductase aremarkedly inhibited by Cd2+ in the range of 1 umol·L-1 to 10 mmol·L-1 .The increase of MDA inmitochondria and microsomes due to Cd2+ was alsoobserved at the final concentration of 25 mmol·L-1 and 25 umol·L-1The increased M DA and de-creased fluiditv of the membranes had a good correla-tion and they all happened in a very short time. Vita-minctreatment had no effect on the fluidity ofmicrosomal membranes, but completely antagonisedthe increase of MDA and partly reduced the degree ofG-6-pase inhibition. The possible mechanism in-volved waS discussed.