Copeptin level in the early prediction of cardiorenal syndrome in rats

Copeptin (CPP) has been considered as a useful marker for prediction of prognosis in heart diseases. However, CPP has not been investigated sufficiently in cardiorenal syndrome (CRS). The present study aimed to investigate the value of CPP level in predicting CRS in rats with partial nephrectomy combined with myocardial infarction (SNX + MI). A total of 60 male Sprague-Dawley rats were used to establish the CRS model by partial nephrectomy combined with MI. The rats were randomly divided into blank control (CK), SNX, MI and CRS groups. Changes in serum and urine CPP concentrations, hemodynamics, blood pressure, and renal function were examined 1-5 weeks after modeling. The predictive values of CPP in the occurrence of CRS in rats were evaluated using receiver operating characteristic (ROC) curve. The results showed that serum CPP in the CRS group in 1-5 weeks and urine CPP in 3 weeks after modeling increased significantly compared with the CK group. Also, serum B-type natriuretic peptide (BNP) in 1 and 3 weeks and urine BNP in 4-5 weeks after modeling increased significantly. No correlation was found between serum or urine CPP, BNP and BUN levels 1 week after modeling in the CRS group. The ROC curve analysis showed that the area under the curve of CRS predicted by serum CPP at 1 week was 0.908 with 56.59 pg/ml as the cutoff point, and its diagnostic sensitivity and specificity were 87.5 and 80.0%, respectively. To conclude, SNX + MI may be used to establish CRS rat model with cardiac and renal damage. Serum CPP may serve as a specific biomarker for the early prediction of CRS.