Objective The present study was to examine the importance of magnesium on the rat antioxidant status.Methods Male Wistar rats were fed with diet containing 0.07%,0.27% and 0.47% of magnesium,respectively.The magnesium serum level and biochemical function analysis were performed after the animals were sacrificed.Results Adding of 0.2% or 0.4% magnesium in diet significantly enhanced activities of antioxidase(P<0.05),and significantly decreased MDA level(P<0.05).There was a significantly difference in the activities of antioxidase between organic magnesium and inorganic magnesium(P<0.05).Conclusion Magnesium-supplemented animals show an decreased susceptibility to an in vivo oxidative stress.

Objective The purpose of the present study was to detect the effect of magnesium on the body's antioxidant system.Methods The feeding periods were divided into parts of 0 to 3 weeks and 4 to 6 weeks.During the first period(0～3 weeks),all the rats in three groups were fed with basal diet which contained only 0.07% magnesium.During the second period(4～6 weeks),one group still continued to be fed the basal diet,the other two were given high Mg(0.27% Mg) supplemented by MgSO_4 or by proteinate magnesium diet.Results During the first period,the level of plasma magnesium was significantly decreased(P0.05).Addition of 0.2% Mg in diet significantly increased the level of plasma magnesium and the activity of some antioxidases(P0.05)and significantly decreased MDA level(P0.05).There was a significant difference between effects of organic magnesium and inorganic magnesium on the activity of antioxidase(P0.05).Conclusion Magnesium-deficient animals show an increased susceptibility to oxidative stress.

Objective To study the effect of dietary levels of Calcium and calcium phosphorous ratio on bone mineralization by growing laboratory beagal dogs.Methods Feeding test,digestive test,slaughter test.Results 0.6% dietary levels of calcium gain less bone mineralization(PO.05).Bone mineral contents increase slightly when dietary calcium level is increased from 1.2% to 3.0%(P0.05).High dietary calcium level has no influence on phosphorous content and high dietary phosphorous level has no influence on calcium content in bone.But high dietary calcium affect magnesium content in bone.Conclusions 1.2% dietary calcium level and 1.2∶1 dietary calcium phosphorous ratio are optimal for bone mineralization.

目的研究低镁后补镁对大鼠机体抗氧化能力的影响。方法试验分两个饲养阶段:0~3周和4~6周。基础日粮含镁0.07%。第一阶段三组动物均饲喂基础低镁日粮;第二阶段,一组继续饲喂基础低镁日粮,第二组饲喂0.27%镁(补无机镁0.2%)日粮,第三组饲喂0.27%镁(补有机镁0.2%)日粮。试验末测血清镁水平,MDA含量和抗氧化酶活性。结果在试验第一阶段,血清镁显著降低(P<0.05),第二阶段添加0.2%镁提高了血清镁和部分脏器某些抗氧化酶活性(P<0.05),降低了MDA水平(P<0.05)。并且添加有机镁比添加无机镁抗氧化酶活性更高(P<0.05)。结论镁缺乏动物机体抗氧化能力下降,缺镁后补镁提高了大鼠机体抗氧化能力。

Magnesium is involved in antioxidant defense mechanisms in the body.Magnesium-deficient animals are more susceptible to free radical injury,supporting the hypothesis that magnesium deficiency reduces the threshold of antioxidant capacity.Inadequate intake of this nutrient has been associated with some diseases,where pathogenic role of free radicals is suggested.This article details the progress in research on influences of magnesium in the body's antioxidant system.