红三叶异黄酮对去卵巢大鼠钙磷代谢及VDR和CaBP-9k mRNA表达的影响

Effects of isoflavones from red clover on calcium/phosphorus metabolisms and on VDR/Cabp-9k mRNA expressions in ovariectomized rats

【目的】研究岷山红三叶(Trifolium pratense cv.Minshan)异黄酮(isoflavone,ISO)调节动物钙、磷吸收与代谢的作用。【方法】选择80只SD(Sprague-Dawley)雌性大鼠(50~60日龄),随机分为8组(每组10只),其中1~7组为去卵巢(ovariectomized,OVX)+红三叶异黄酮组,分别按320、160、80、40、20、10和0 mg/(kg·d)的量灌胃红三叶异黄酮,第8组为假手术组,灌服等量生理盐水,试验期60 d。【结果】40~320 mg/(kg·d)的灌服量可提高去卵巢大鼠血清钙含量,大鼠胫骨灰分、胫骨钙含量和钙磷比均随灌服量上升而增高;20~40 mg/(kg·d)灌服量上调大鼠小肠VDR mRNA及CaBP-9K mRNA的表达促进小肠对钙的吸收,160~320 mg/(kg·d)灌服量上调大鼠肾脏VDR mRNA的表达促进肾小管对钙、磷的重吸收。【结论】岷山红三叶异黄酮对去卵巢大鼠小肠钙吸收和肾脏钙重吸收及骨的生长、矿化有一定促进作用。

【Objective】The study aimed to explore the effect of isoflavones from Minshan red clover on the absorption and metabolism of calcium and phosphorus in animals and the underlying mechanisms.【Method】We selected 80 Sprague-Dawley female rats(50~60 days old)and divided them into 8 groups(10 rats in each group)randomly.Among them,1-7 groups were ovariectomized and intragastrically administrated with red clover isoflavones,the doses of which were 320,160,80,40,20,10 and 0 mg/(kg·d),respectively,and the group 8 was a sham operation group,which was perfused with the same amount of normal saline for 60 days.【Result】The doses of 40~320 mg/(kg·d)could increase the serum calcium content of the ovariectomized rats,and the tibial ash content,tibial calcium content and calcium phosphorus ratio of rats increased with the dose increasing.The dose of 20~40 mg/(kg·d)could up-regulate the expression of VDR mRNA and CaBP-9K mRNA in small intestine of rats and promoted the absorption of calcium in small intestine,and the doses of 160~320 mg/(kg·d)could upregulate the expression of VDR mRNA in rat kidney and promote the reabsorption of calcium and phosphorus in renal tubules.【Conclusion】The isoflavones from Minshan red clover can promote calcium absorption in small intestine,reabsorption in kidney,and bone growth and mineralization of the ovariectomized rats.