Early Prediction Of Zinc-α2-glycoprotein For Contrast-induced Nephropathy And Inducing Apoptosis In Rat Renal Tubular Epithelial Role With Iodine Contrast Agent

Objective:Contrast media-induced nephropathy(CIN) is a known complication ofin-hospital acute renal failure.Currently there is no effective biological markers,theserum creatinine defects in terms of sensitivity and specificity of diagnosis of CIN.Therefore, It is important for the prevention of CIN to find a sensitive and specificbiological markers,which could be detected at an early CIN.This study detect the levelof urine zinc-α2-glycoprotein(ZAG) in patients of PCI with low-osmolar contrastmedia,and relationship between ZAG expression and cell apoptosis that iodine contrastmedia(CM) induced rat renal tubular epithelial cells (NRK-52E).To evaluate levels ofurine ZAG for early prediction of CIN, and preliminarily ZAG role in the pathogenesisof CIN.Method:Select cardiology patients undergoing PCI (including unstableangina,acute myocardial infarction patients and old of)10cases,All patients wereinformed consent. CM is hypotonic non-ionic monomer contrast agent ioversol370.Contrast media injection methods are Judkins coronary angiography andinterventional treatment based onintraoperative findings coronary artery stenosis.Theinclusion criteria:All patients were underwent PCI surgery and taken blood beforeoperation to detection of serum creatinine (Scr) and estimated glomerular filtrationrate(eGFR) was calculated according to the MDRD formula,eGFR≥90ml/min·1.73m2.Exclusion criteria:1)Chronic kidney disease;2) Various reasons cause acute renal insufficiency, such as the recent use of nephrotoxic drugs, pre-renal ischemia and soon.3)Diabetes, hyperlipidemia, cancer patients;4) patients received angiography within7days. Preoperative and postoperative2h,24h urine specimens form all patients,-40℃refrigerator. All urine specimens were detected urine creatinine levels and ZAGconcentrations by ELISA.The levels of urine ZAG are showed with ratio of ZAGconcentration and the urine creatinine(mg/g),meanwhile taking blood samples beforeangiography to detect biochemical indicators include: serum creatinine, blood ureanitrogen, cholesterol, triglycerides, low-density lipoprotein.Cultured rat renal tubularepithelial cells(NRK-52E),the NRK-52E are cultured at different dose (25,50,100,125mgI/ml) for6h and at same dose(100mgI/ml) for2h,4h,6h.Cell apoptosis aredetected with Annexin V-FITC/PI double stains.The protein expression of ZAG wasexamined by Western blot.Result:There are6males and4females in10patients:mean age58.40±6.50yearsold, blood urea nitrogen5.98±0.67mmol/L, cholesterol3.97±0.76mmol/L, triglycerides1.39±0.34mmol/L, low density lipoprotein2.09±0.57mmol/L, the amount of contrastmedia101.00±15.24ml, Scr63.83±9.65umol/L, eGFR104.07±11.08ml/min·1.73m2.The levels of preoperative urinary ZAG were22.85±11.10mg/g,the levels ofpostoperative2h、24h urinary ZAG were67.44±44.94mg/g、32.24±18.55mg/g.Compared with preoperative the levels of urinary ZAG, postoperative2h urinary ZAGare higher, the difference was statistically significant(p <0.05). Though the levels ofpostoperative24h urinary ZAG are lower than2h urinary ZAG, but still higher thanbefore the surgery, the difference was not statistically significant(p>0.05).ZAG levels ineach group and blood biochemical parameters are not correlated.Cultured NRK-52Ecells, iodine can induce NRK-52E cell apoptosis in concentration-dependent and atime-dependent manner (P <0.05, n=3).ZAG concentration of protein expression isincreased in concentration-dependent(P <0.05, n=3) and a time-dependent manner (P<0.05, n=3).Linear regression analysis showed that ZAG protein expression and cellapoptosis rates were positively correlated. Conclusion:1.The hight levels of urinary ZAG can show early acute renal damagethat iodine contrast media induced.2.ZAG protein expression associated with increased apoptosis of renal tubularepithelial cells in CM induced NRK-52E cells.