高血磷对5/6肾切除大鼠肾Ⅱa型钠-磷协同转运子基因表达的影响及司维拉姆的干预作用  

Effect of hyperphosphatemia on type IIa sodium-dependent phosphate cotransporter mRNA expression in the kidney of 5/6 nephrectomized rats and the interference of Renagel

作　　者：曾鸣[1] 王笑云[1] 王小兵[1] 赵秀芬[1] 

机构地区：[1]南京医科大学第一临床医学院肾内科,210029

出　　处：《中华肾脏病杂志》2005年第7期408-412,共5页Chinese Journal of Nephrology

基　　金：江苏省科技厅社会发展基金资助项目(BS99730)

摘　　要：目的研究高血磷对5/6肾切除大鼠肾脏Ⅱa型钠-磷协同转运子(NaPi-2)mRNA表达的影响及司维拉姆(Renagel)的干预作用。方法42只SD大鼠,随机分为5/6肾切除加高磷饲料组(STNx+HP)(含P1.2%)、5/6肾切除加低磷饲料组(STNx+LP)(含P0.2%)、5/6肾切除加正常磷饲料组(STNx+NP)、5/6肾切除高磷饲料+Renagel组(STNx+HP+Ren)(Renagel在饲料中占2%)、假手术高磷饲料组(Sham+HP)、假手术低磷饲料组(Sham+LP)、假手术正常磷饲料组(Sham+NP)。术后14d,测定血清离子钙(iCa)、磷(P)、全段甲状旁腺激素(iPTH)、血1,25-(OH)2D3和尿磷酸盐排泄分数(FEp)。RT-PCR检测NaPi-2mRNA在肾脏的表达。结果STNx+Hp组的血P、iPTH明显高于STNx+LP组及假手术3个组(P均<0.05);上述5个组间的血iCa、1,25-(OH)2D3差异无统计学意义(P均>0.05)。STNx+LP组血P、iPTH均明显低于STNx+HP组(P均<0.05)。STNx+HP组较STNx+LP组肾NaPi-2mRNA表达明显减少(P<0.01)。STNx+HP+Ren组较STNx+HP组NaPi-2mRNA表达明显增加。结论高磷血症是促进5/6。肾切除大鼠血iPTH增高且不受钙和1,25-(OH)2D3影响的独立因素。高磷显著地降低5/6肾切除鼠肾NaPi-2mRNA表达,而司维拉姆能显著降低血磷及iPTH,增加肾NaPi-2mRNA表达。Objective To investigate the effect of hyperphosphatemia on type Ⅱa sodium dependent phosphate cotransporter (NaPi-2)mRNA expression in the kidneys of 5/6 nephrectomized (STNx)rats and evaluate the interference of Renagel. Methods Forty-two male Sprague-Dawley rats underwent 5/6 nephrectomy or sham operation. The animals were then divided into seven groups: (1)STNx+high-Pi diet(HP) group (1.2%P); (2)STNx+low-Pi diet(LP) group(0.2%P); (3)STNx+ normal-Pi diet (NP) group; (4)STNx+HP+Renagel-treated (Ren)group; (5)sham+HP group; (6) sham+LP group; (7)sham+NP group. Serum ionized calcium (iCa) , phosphorus, and iPTH levels were detected at day 2,7,14.The kidneys were removed after the rats were sacrificed on day 14 and serum 1,25-(OH)2D3 and FEp were measured. RT-PCR was applied to examine NaPi-2 mRNA. Results Serum P and iPTH levels in STNx+HP group were significantly higher than those in STNx+ LP and 3 sham groups (P<0.05). Meanwhile, there were no significant differences in iCa or 1,25-(OH)2D3 (P>0.05)among these five groups mentioned above. Serum P and iPTH levels in Renagel-treated group were much lower than those in STNx+HP group (P<0.05). The expression of NaPi-2 mRNA was significantly decreased to a larger extent in STNx+HP group than that in STNx+LP group (P<0.01).The expression of NaPi-2 mRNA was much higher and FEp was much lower in Renagel-treated rats than those in STNx+HP rats (P<0.05). Conclusions Hyperphosphatemia is perhaps a factor to increase iPTH level independent of iCa and 1 ,25-(OH)2D3. High-Pi diet can reduce the expression of NaPi-2 mRNA in rat kdineys. Renagel can decrease the level of serum P and iPTH, and enhance the expression of NaPi-2 mRNA.

关 键 词：肾切除大鼠 司维拉姆 干预作用 转运子 Ⅱa型 高血磷 基因表达 协同 mRNA表达 5/6肾切除 全段甲状旁腺激素 iPTH 钠 血清离子钙 PCR检测 SD大鼠 排泄分数 高磷血症 独立因素 饲料 手术 磷酸盐 iCa 统计学 低血磷 肾脏 

分 类 号：R692.5[医药卫生—泌尿科学]