Effects of aminoguanidine and vitamin C on collagen type IV in diabetic nephropathy rats.

The aim of this article is to investigate the effects of Aminoguanidine and vitamin C (VitC) on type IV collagen in diabetic nephropathy rats. Diabetic nephropathy rats were induced by intraperitoneal injection of STZ. Rats were randomly divided into five groups: normal control group (n = 10), diabetes group (n = 10), aminoguanidine group (n = 10), VitC group (n = 10), aminoguanidine and VitC group (n = 10). After 16 weeks, the general conditions, blood gloucose, glycosylated hemoglobin, blood urea nitrogen, serum creatinine, serum type IV collagen, urinary albumin excretion rate, and creatinine clearance rate were detected, type IV collagen protein was determined by immunohistochemical analysis as well as the expression of collagen type IVα1 mRNA were determined by in situ hybridization analysis in the kidneys of each group. The results were (1) diabetes mellitus and renal lesions occurred in the diabetes group, aminoguanidine group, VitC group, VitC and aminoguanidine group; (2) aminoguanidine and VitC improved the general conditions of diabetic nephropathy rats, decreased blood urea nitrogen, serum creatinine, and urinary albumin excretion rate as well as increased creatinine clearance rate. The expressions of collagen type IV were significantly down-regulated in treatment groups in contrast to the diabetes group. Aminoguanidine and VitC protect renal lesions in diabetic nephropathy, respectively, by inhibiting expression of type IV collagen, while aminoguanidine and VitC have a synergistic effect on them.