不同钙源高钙日粮对青年蛋鸡肾损伤及p53蛋白表达的影响

将120羽40日龄伊沙蛋鸡随机分成3组,每组40羽,分别为：对照组（根据禽类营养需求饲喂正常日粮,含钙0.9%）,试验组1（石粉高钙日粮组,含钙3.78%）,试验组2（磷酸氢钙高钙日粮组,含钙3.78%）,进行为期65d的饲养试验。试验后65d,对各组鸡作血清中钙、磷、尿酸、肌酐和尿素氮的测定,并用免疫组织化学方法检测肾脏中p53蛋白的表达情况。结果表明,高钙组鸡肾脏都有一定程度的损伤,与对照组相比,试验组1中血清尿酸、尿素氮,肌酐显著升高（P〈0.05或P〈0.01）,血清磷极显著降低（P〈0.01）;试验组2中血清尿素氮极显著升高（P〈0.01）,血清磷极显著下降（P〈0.01）,血清钙、尿酸差异不显著（P〉0.05）;与试验组1相比较,试验组2血清磷极显著升高（P〈0.01）,血清钙、尿素氮、尿酸、肌酐差异不显著（P〉0.05）。试验组1鸡肾小管上皮细胞（LLC-PK1）中黄色颗粒很多,p53呈强阳性;试验组2鸡LLC-PK1中黄色颗粒较多,p53呈中等阳性。结果提示,不同钙源高钙日粮能致青年蛋鸡肾损伤,并能够促进肾小管上皮细胞p53蛋白的高表达。

Effects of high dietary calcium from different sources on renal injury and p53 protein expression in chicken growers

One hundred and twenty ISA growers aged 40 days were randomly divided into 3 groups with 40 growers each. The groups were： control group （semisynthetic commercial layer standard diet in accordance with the nutrient requirements of poultry, Ca 0. 9 %, DM basis）; group 1 （high dietary calcium supplementation from limestone, Ca 3.78% ,DM basis） ; group 2 （high dietary calcium supplementation from CaHPO4 ,Ca 3.78% ,DM basis）. All chickens were reared for 65 days under normal condition. Calcium, phosphorus, uric acid, creatinine and urea N in serum were detected. Immunohistochemistry was used to detect the p53 protein expression on 65 d. The results showed high dietary calcium cause the renal damage. Compared to the control group, uric acid, urea N and creatinine increased （P〈0.05 or P〈0.01） and phosphorus decreased in serum of group 1 （P〈0.01）. Urea N increased （P〈0.01） and phosphorus decreased in serum of group 2 （P〈0.01）. Phosphorus in serum of group 2 increased when compared with the group 1 （P〈0.01）. p53 protein was expressed in kidney tissues of growers feeding high dietary calcium,es pecially the positive cells appeared in the epithelial cells of renal tubule （LLC-PK1）. Expression of p53 protein of LLC-PK1 in group 1 was strong. Positive signal of p53 protein of LLC-PK1 in group 2 was moderately. The results indicated that high dietary calcium could cause the renal damage and promote the expression of p53 protein in the ep- ithelial ceils of renal tubule.