Mechanism of renal injury and apoptosis in rats with nephrotic syndrome induced by mercury

Objective: To investigate the relationship between renal injury and apoptosis in rats with nephrotic syndrome induced by mercury, in order to find out the pathogenesis. Methods: Forty-eight healthy male SPF-grade BN (Brown-Norway) rats were divided into the control group and the exposure group by random number table. The nephrotic syndrome was caused by subcutaneous injection of HgCl(2) (1 mg/ml) in the abdominal weight per kg of body weight. The control group was injected with the same volume of NaCl as the exposure group. Some rats were sacrificed on the 14th, 21st, 28th, and 35th days, and the serum kidney injury indicators creatinine (CRE) and urea nitrogen (BUN) were detected, and the renal tissue mercury content was detected; the in situ terminal transferase labeling technology (TUNEL) was detected Apoptosis, immunofluorescence detection of Cyt C content, Western blot detection of mitochondrial pathway apoptosis-related proteins [B-cell lymphoma 2 (Bcl-2) , Bcl-2 related X protein (BAX) , cysteine proteinase 3 (Caspase 3) ], mitogen-activated protein kinase (MAPK) signaling pathway-related proteins[p38 mitogen-activated protein kinase (P38MAPK) , extracellular regulatory protein kinase (ERK) ] expression. Results: Compared with the control group, the BUN content in the serum of rats in the exposure group was significantly increased on days 7, 21, and 28, the CRE content was significantly increased on 21 days, the CRE content was significantly decreased on 28 and 35 days, and the organ coefficient and renal mercury content were 14 to 35 days. Significantly increased, and the differences were statistically significant (P<0.05) . Compared with the control group, rats in the exposed group showed increased glomerular stroma, tubule dilatation and other renal cell apoptosis at 14 to 35 days, and Cyt C expression was obvious in the exposed groups at 14, 21 days. Compared with the control group, the BAX content of the rats in the exposed group was significantly increased on the 21st day, the content of Caspase 3 in the rats on the 14th and 21st days was significantly increased, and the content of the P38MAPK in the 35th day was significantly increased (P<0.05) . Conclusion: HgCl(2) may cause renal cell damage through the mitochondrial pathway of apoptosis and cause nephrotic syndrome, and the MAPK signaling pathway may regulate this process and exert an inhibitory effect on apoptosis.