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目的 研究饲料缺镁或高镁对生长期大鼠钙、磷、镁吸收代谢以及骨骼发育的影响。方法 30只 SD大鼠 ,分为三组 ,每组 1 0只 ,单独喂养在有机玻璃代谢笼中 ,第一组大鼠饲喂缺镁饲料 (含镁 86mg/kg) ,第二组饲喂适量镁饲料 (含镁 548mg/kg) ,第三组为高镁饲料 (含镁540 2 mg/kg) ,三组饲料均为人工半合成制备 ,其中含钙 3.7g/kg,含磷 4g/kg。经过 2 5天对喂养方法及代谢笼的适应后 ,开始 5天期的代谢实验。每天记录大鼠的进食量 ,分别收集每个大鼠的粪、尿。代谢实验结束后 ,禁食 1 2 h,在乙醚麻醉下 ,心脏采血并处死大鼠 ,取股骨、胫骨测定重量、长度和体积后 ,与肾脏一起储存于 - 2 0℃ ,待测钙、镁和磷的含量。结果 缺镁和适量补镁对钙的表观吸收基本没有影响 (86% ) ,饲料中过量的镁使大鼠钙的表观吸收略有下降 (83% ) ,高镁使尿钙排出显著增加 ,降低了钙在体内的滞留 ;饲料高镁使磷的表观吸收显著下降。但尿磷排出减少 ,磷在体内滞留反而增加。随着饲料中镁含量的增加 ,粪和尿中镁的排泄均大幅度上升 ,可见镁的内环境稳定由肠道和肾脏共同调节。结论 低镁和高镁饲料均不利于生长期大鼠骨骼的生长发育。低镁饲料使大鼠肾钙、磷蓄积 ,可能是肾结石形成的主要原因。
Objective To study the effects of dietary magnesium or magnesium on the absorption, metabolism and bone development of calcium, phosphorus and magnesium in rats during the growth period. Methods Thirty SD rats were randomly divided into three groups with 10 rats in each group. The rats in the first group were fed with Mg-free diet (containing magnesium 86 mg / kg) and the second group fed The third group was high magnesium feed (containing 540 mg / kg of magnesium). The three groups of feed were all prepared by artificial semi-synthesis, including 3.7g / kg calcium and 4g / kg. After 25 days of feeding method and metabolic cage adaptation, start a 5-day metabolic experiment. The daily food intake of rats were collected for each rat’s feces and urine. Metabolic test after the end of fasting 12 h, under ether anesthesia, the heart blood and rats were sacrificed, take the femur, tibia weight, length and volume were measured, stored together with the kidneys at -20 ℃, to be tested calcium and magnesium And phosphorus content. Results Magnesium deficiency and proper magnesium supplementation had no effect on the apparent absorption of calcium (86%). Excess magnesium in the feed decreased the apparent calcium absorption slightly (83%), while magnesium increased the urinary calcium excretion , Reducing the retention of calcium in the body; feed magnesium significantly decreased the apparent absorption of phosphorus. However, decreased urinary phosphate emissions, phosphorus retention in the body but increased. With the increase of magnesium in feed, excretion of excretion of magnesium in excrement and urine increased sharply. It can be seen that the internal environment of magnesium is regulated by intestinal tract and kidney. Conclusion Both low magnesium and high magnesium feed are not conducive to the growth and development of bone in the growing stage. Low magnesium feed rat kidney calcium, phosphorus accumulation, kidney formation may be the main reason.