低镁对肉仔鸡红细胞体外氧化应激敏感性及红细胞膜流动性的影响

为研究镁对肉仔鸡红细胞体外氧化应激的敏感性和红细胞膜流动性的影响,本试验用96只1日龄的AA肉仔鸡随机分配为低镁日粮组(镁含量1.2 g/kg)和对照组(镁含量2.4 g/kg)。在体外氧化应激反应体系中,低镁组肉仔鸡红细胞丙二醛(MDA)的生成量高于对照组(P<0.01),低镁日粮显著提高红细胞膜的各向异性参数(P<0.05);低镁组肉仔鸡红细胞的谷胱甘肽(GSH)含量降低了17%,丙二醛(MDA)的含量升高了19%(P<0.05),红细胞膜的镁含量降低18%(P<0.05);低镁日粮组肉仔鸡红细胞膜胆固醇的含量(P<0.05)及胆固醇/磷脂比(P<0.01)均显著提高。结果表明表明低镁日粮削弱了红细胞的抗氧化系统从而提高红细胞对体外氧化应激的敏感性;红细胞膜胆固醇含量的提高和丙二醛(MDA)的积累可能是低镁日粮降低红细胞膜流动性的原因。

Effects of low-magnesium on susceptibility of erythrocyte to in vitro oxidative stress and erythrocyte membrane fluidity in broiler chickens

The objective of this study was to investigate effects of magnesium on susceptibility of erythrocyte toin vitro oxidative stress and membrane fluidity in broiler chickens.Ninety six-1day-old male Abor Acre broiler chicks were ran-domly allocated into low-magnesium and control groups,each group had6replicates of8male birds each,fed either control or low magnesium diets containing about1.2g/kg or2.4g/kg of diet respectively.The erythrocyte from low-magnesium group exhibited higher MDA production inin vitrooxidative stress reaction system than that from control(P<0.05).The anisotropy parameter of erythrocyte membranes was increased by low magnesium diet(P< 0.05).Glutathione(GSH) content of erythrocyte decreased by17%(P<0.05) while malondialdehyde(MDA) concentration increased by19% in low-magnesium group(P<0.05).Magnesium content of erythrocyte membrane from low-magne-sium group was reduced by14%(P<0.05).Feeding low-magnesium diet for21days resulted in a smaller but signifi-cant increase in cholesterol content of erythrocyte membrane(P< 0.05) and in higher cholesterol/phospholipids ratio(P<0.01).These results suggest that low magnesium diet impaired antioxidant capacity of erythrocyte and then in-creased susceptibility of erythrocyte toin vitrooxidative stress.Increased MDA content and altered cholesterol compo-sition of erythrocyte membrane should be contributing factors to the decrease of erythrocyte membrane fluidity.