Correlation between the ratio of intima/media thickness and inflammatory factors in renal small artery of diabetic nephropathy rats / 中华肾脏病杂志

ABSTRACT

Objective To observe the change of intima/media thickness ratio and expression of inflammatory factors in renal small artery of diabetic rats, and to explore the correlations of intim/media ratio with inflammatory factors and vascular lesions of diabetic nephropathy (DN) rats. Methods Seventy healthy SD rats were randomly divided into diabetic nephropathy group (DN, n=40) and normal control group (N, n=30). DN rat model was induced by intraperitoneal injection of streptozotocin (STZ). Thirty-five DN rats were successfully established. N group received same dose of citrate buffer. Rats were sacrificed after 4, 12, 24 weeks respectively.The intima/media thickness ratio in renal small artery was detected by immunofluorescence. The monocyte chemoattractant protein-1 (MCP-1) protein and mRNA expression of renal small artery were detected by immunohistochemistry and in-situ hybridization at each time point. Results Blood glucose and urine protein excretion (24 h) at different time points in DN group were significantly higher than those of N group (P＜0.05). From the 12th week, Scr, BUN, serum phosphorus were significantly higher than those of N group (P＜0.05). At the 4th week, renal small artery had the expression of MCP-1 protein and mRNA. The expression increased gradually with time, reached the highest at the 24th week, and was significantly higher than that of N group at each time point (P＜0.05). Immunofluorescence results showed that as compared to N group, in the first 4 weeks, intima/media thickness ratio in DN group was not different, at the 12th week the ratio was higher but without significant difference, at the 24th week the ratio was significantly higher (P＜0.05). Small artery intima/media thickness ratio of DN group was positively correlated with MCP-1, cholesterol, triglyceride, serum phosphate (r=0.742, P＜0.01; r=0.740, P＜0.01; r=0.829, P＜0.01; r=0.580, P＜0.01). Conclusions The arterioles intima/media thickness ratio of early DN is significantly correlated with MCP-1, lipids and phosphorus. MCP-1 may be involved in the DN vascular disease.