钙吸收利用与钙摄入量关系的动物实验研究

为探讨钙吸收利用与钙摄入量间的相互关系 ,给初断乳Wistar大鼠喂饲 3周缺钙饲料后 ,按体重随机分为缺钙组、钙适宜组和高钙组 ,进行 12周喂养 ,并于实验第 5周进行 3天代谢试验。结果表明 ,适宜补钙可明显增加骨钙、骨密度、骨矿物质含量和股骨的重量 (P <0 0 5 ) ,加大补钙剂量 ,补钙效果未见增加。相关分析发现摄入钙与骨钙、骨密度、骨矿物质含量呈正相关 ,而与吸收率、存留率呈负相关。量效研究发现 ,大鼠钙摄入量 (X)与吸收率 (^Y)间的关系呈双曲线函数形式 ,所得回归方程为 :^Y =e6 80 68×X- 0 882 1 +2 0 ,(F =47 315 4,P <0 0 0 0 1)。实验结果显示 ,用原子吸收分光光度计测定 ,骨钙与用单光子骨密度仪测定的骨矿物质含量具有良好的线性关系

Effect of different doses of calcium in rats'diet on absorption and utilization of calcium

The relation among Ca-intake,Ca-absorption rate,Ca-retention rate and bone status in rats was studied.Thirty-six weaning male and female rats,were fed with Ca-deficient diet for three weeks,then the rats were randomly divided into three groups(low-dose,middle-dose and high dose calcium).The rats were fed for 90 days.The calcium metabolism tests were carried out by the end of the fifth week.The result showed that adequate calcium increased bone calcium,bone mineral density,bone mineral content and femoral weight in rats remarkably(P<0.01),but higher dose of supplemented calcium had no further improvement on calcium nutrition status.There were positive correlation between Ca-intake and bone calcium,bone mineral density and bone mineral content,and negative correlation between Ca-intake and Ca-absorption rate,Ca-retention rate.The dose-effect analysis demonstrated that the change of Ca-absorption()with Ca-intake(X) was in a trend of hyperbola.The regression equation was =e 6.8068×X -0.8821+20,(F=47.3154,P<0.0001).A satisfactory line regression between bone calcium and bone mineral content was also demonstrated.