The Role Of Mast Cells In The Renal Tissues Of Diabetic Nephropathy Rats

Objctive:Diabetic nephropathy, a serious disease, is hazardous to human health. Its incidence is rising year by year. However, the pathological mechanism is still unclear. There is not any effective treatment for the prevention of diabetic nephropathy yet. In the previous study, we found that, mast cells increased notably in the renal tissues of diabetic nephropathy patients, and·the increase of mast cells is also correlated significantly with the progression of diabetic nephropathy, which suggest that mast cells may play important roles in the development of diabetic nephropathy, and could be expected to become a new target of the prevention and treatment of diabetic nephropathy. The purpose of this research is to investigate the pathological significance of mast cells in the renal tissues of diabetic nephropathy rats.Methodology:Rats were divided into control group and treatment group. The treatment group was fed with high-glucose and high-fat diet for one month, and then injected intraperitoneally with low dose streptozotocin for5times (30mg/kg), while the control group was fed with normal chow without any treatment. In the treatment group, blood, urine, and renal tissues were collected at the1st week,4th week,8th week,16th week and24th week after modeling successfully. All the specimens were collected from the same age rats in the control group. Blood glucose, serum triacylglycerol, serum cholesterol, blood urea nitrogen, serum creatinine, urine glucose,24-hour urinary protein excretion were detected. The pathological indices (including glomerular volume, medullary loop cavity expansion, mesangial proliferation, renal tubular epithelial cell foam degeneration, tubulointerstitial fibrosis, inflammatory cell infiltration, vascular hyalinization) were analysed. The infiltration of mast cells in the kidney was detected by tryptase immunohistochemical staining. The differences of biochemical indices, pathological indicators, and the amount of mast cells in the renal tissues between the two groups were analyzed.Results:High-glucose and high-fat diet plus multiple injection with low dose streptozotocin intraperitoneally could induce diabetes in rats, which showed polydipsia, polyuria, high blood glucose, and high cholesterol. One month after modeling successfully, the rats had some symptoms of diabetic nephropathy, such as increased glomerular volume, expanded medullary loop cavity, increased urine protein, increased blood urea nitrogen. But there was no obvious tubulointerstitial fibrosis. The tryptase immunohistochemical staining showed that mast cells were found in rats’ renal tissues of both groups, and the number of mast cells in the treatment group was significantly more than the control group.Conclusion:The number of mast cells in the diabetic nephropathy rats was significantly more than the control group, which prompted that mast cells may play important roles in diabetic nephropathy.