低磷条件下VD_3对大鼠小肠NaPi-Ⅱb mRNA表达及磷吸收的调控  

Regulation of Vitamin D_3 on Intestinal NaPi-Ⅱb mRNA Expression and Pi Uptake of Rat Under Low Phosphate

作　　者：曹满湖[1] 贺建华[1] 方热军[1] 陈娟[1] 

机构地区：[1]湖南农业大学动物科学技术学院,长沙410128

出　　处：《中国农业科学》2010年第18期3838-3847,共10页Scientia Agricultura Sinica

基　　金：湖南省自然科学基金资助项目(08JJ3084);湖南省教育厅项目(08C42500)

摘　　要：【目的】本试验旨在研究低磷条件下VD3对磷吸收的调节作用。【方法】选择40只断奶后大白鼠(雄),随机分为0.2%(低磷组)和0.6%(正常磷组)两磷(总磷)水平组,每组5个重复,每重复4只大白鼠,试验期7d。试验前6d,每组每只大白鼠肌注VD3代谢抗干忧药物EHDP(二磷酸盐);宰前的12h,每组2只老鼠以600ng/kg.wt剂量注射VD3,为试验组;另2只不注射,为对照组。第7天早晨屠宰、取样。测定血清和骨组织中钙磷及小肠NaPi-Ⅱb载体蛋白mRNA表达量和磷的吸收等指标。【结果】(1)低磷水平对照组骨钙、骨磷分别比正常磷水平低3.33倍(P<0.01)和3.03倍(P<0.01)。两磷水平试验组VD3含量比对照组高3.08倍和2.32倍,差异极显著;(2)0.2%磷水平小肠各段和肾脏Na+/PiⅡb mRNA表达量试验组皆极显著高于对照组;(3)两磷水平试验组4个部位磷的吸收皆显著或极显著高于对照组,0.2%磷水平试验组较对照组磷吸收4个部位分别提高:51.76%、62.68%、57.79%、47.37%。0.6%磷水平组分别提高18.19%、39.22%、54.72%、39.83%。【结论】(1)低磷情况下,VD3是调节磷吸收的一个重要因素,补充VD3可提高NaPi-Ⅱb转运蛋白mRNA的表达和磷的吸收;(2)VD3对磷吸收的提高作用随着磷水平的增加而减弱。Objective A study was conducted to determine the role of vitamin D3 in regulating phosphate（Pi） intake.Method A total of 40 male Kunming-rats aged at 21days was randomly divided into 2 treatments,each treatment consisted of 5 replicates with 4 rats.The two treatments were fed with the basal diet supplemented with 0.2 %（low-Pi） or 0.6 %（normal-Pi） phosphate（total phosphate）.The experiment lasted for 7 days.On the former 6 days,each of the replicates was treated with EHDP（ethane-1-hydroxy-1,1-diphosphonicacid,tetrasodiumsalt） which is known to decrease the circulating levels of 1,25-（OH）2D3.Before twelve hours before slaughter,two of the replicates were injected with 1,25-（OH）2D3 at 600ng/kg.wt,and used as treatment group,the no 1,25-（OH）2D3 injection group was used as control.On the 7th day morning,rats were slaughtered for determination of Ca（calcium） and Pi（phosphate） concentration and phosphate uptake.Result Results showed that phosphate levels significantly affected the Ca and Pi concentration of bone;That of low-Pi treated group was 3.33 folds（P0.01） and 3.03 folds（P0.01） than normal Pi treatment under VD3 stress;VD3 concentration of the two treatment groups was 3.08（P0.01） folds and 2.32 folds（P 0.01）higher than the control group.NaPi-IIb mRNA expression of 0.2 % Pi treatment group was significantly higher than the control group.NaPi-IIb mRNA expression in ileum and duodenum of 0.2% Pi treatment group was 14.53 folds higher and 9.80 higher folds than 0.6% Pi treatment group,and the difference was significant（P0.01）.Pi uptake of treatment groups of two phosphate levels was significantly（P0.01 or P0.05） higher than the control group,respectively by51.76%,62.68%,57.79%,and 47.37% of in ileum,jejunum and duodenum and renal in 0.2% Pi treatment group,while 18.19%,39.22%,54.72%,and 39.83% in 0.6 % Pi treatment group.ConclusionThe results showed that vitamin D3 plays an important role in regulation Pi uptake under low phosphate.Injection of 1,25-（OH�

关 键 词：NaPi-Ⅱb 低磷 吸收 VD3 大白鼠 

分 类 号：S865.13[农业科学—野生动物驯养]