低蛋白饮食加α-酮酸对减轻腺嘌呤慢性肾功能衰竭大鼠模型血管钙化的作用

Effects of low protein diet supplemented with α-ketoacid on aorta ventralis calcification in adenine-induced chronic renal failure rats

目的:观察低蛋白饮食加α-酮酸(LPD+α-KA)这一终末期肾功能衰竭(ESRD)病人营养治疗方法对减轻血管钙化的作用。方法:将18只大鼠随机分为正常对照组、正常蛋白-慢性肾功能衰竭(NPD-CRF)组和LPD+α-KA-CRF组。两组CRF大鼠饲料中含0.75%腺嘌呤。于喂养6周后留取血标本和腹主动脉,测定血钙、磷等生化指标,并采用H-E和Von-Kossa染色,观察各组动物腹主动脉血管壁的钙化程度。结果:与正常对照组比,两组CRF大鼠血肌酐水平均显著升高。NPD-CRF组表现为低钙高磷;LPD+α-KA-CRF组仅血钙显著升高,两组大鼠钙磷乘积均高于正常对照组。NPD-CRF组H-E染色示腹主动脉中层弹力纤维层数减少,排列紊乱,且弹力纤维迂曲断裂。经Von-Kossa染色可见弥漫的蓝黑色颗粒沉积,普遍发生钙化;而LPD+α-KA-CRF组大鼠血管壁中层弹力纤维结构尚完整,仅偶见蓝黑色颗粒沉积,钙化程度较轻。结论:腺嘌呤CRF大鼠模型存在钙磷代谢异常、血管钙化现象。LPD+α-KA可改善低钙高磷血症,并有助于减轻血管钙化程度。

Objective：This study was aimed to evaluate the effects on the vascular calcification of low protein diet supplemented with α-ketoacids（LPD＋α-KA） in comparison with normal protein diet（NPD） in adenine induced CRF rat model.Methods：Eighteen male Wistar rats were divided into 3 groups：1.control（n=6）;2 NPD-CRF（n=6）,feeding a synthetic diet containing 0.75% adenine and 22% casein;3.LPD＋ KA（casein 4%＋ KA 2%）,n=6.All the rats were sacrificed at week 6.Serum creatinine,BUN,calcium and phosphorus were measured.HE and Von kossa stain of aorta ventralis was performed to observe the vascular calcification.Results：Lowering the protein content of the diet from 22 to 4% supplemented with 2% α-KA dramatically decreased the extent of aorta ventralis calcification and the levels of serum phosphate and BUN in uremic rats,increased the serum calcium level simultaneously without significantly affecting the elevation in serum creatinine and Ca x P product.Conclution：This observation suggests that low protein intake with-Ketoacid diet could be a protective factor for medial artery calcification in uremic model.