Expression of matrix metalloproteinases-2 and tissue inhibitor of metalloproteinase-2 in glomerular of adriamycin-induced nephrotic rats

Objective To investigate the expression and significance of matrix metalloproteinases-2(MMP-2) and tissue inhibitor of metalloproteinase-2(TIMP-2) in glomerular of adriamycin-induced nephritic rats.Methods Twenty-five Sprague-Dawlay(SD)male rats,were randomly divided into two groups on average,including control group(n=10) and observation group(n=15).Seven point five mg·kg-1(diluted with saline to 3 mL) adriamycin was injected in tail vein in observation group.The equal amount of physiological saline was injected in tail vein in control group.Gastric lavage with 10 mL·kg-1 physiological saline with one time per day were given in two groups for eight weeks.The expressions of MMP-2 and TIMP-2 in nephridial tissue were examined by reverse transcription-polymerase chain reaction.Results Compared with control group at eight weeks,the level of 24 hours urinary protein count,serum creatinine and blood urea nitrogen were increased significantly in observation group(P0.01),the albumin was decreased significantly(P0.01).The glomerular capillary loops in renal cortex were clear and no extracellular matrix(ECM) accumulation in control group;The visible part of the capillary lumen in renal tissue narrowing or even occlusion,the renal capsule expansion,wall thickening and balloon adhesion were observed in observation group.The mRNA expression of MMP-2 and TIMP-2 and the mRNA semi-quantitative ratio of MMP-2/TIMP-2 in observation group were reducer significantly than those in control group(P0.01).Conclusion MMP-2 and TIMP-2 play an important role during the glomerulosclerosis course of adriamycin-induced nephropathy.The imbalance ratio of MMP-2 and TIMP-2 results in the reduction of glomerular ECM degradation,results in excessive accumulation of ECM,and takes part in the development of glomerulosclerosis.