AIM:To observed the protective effect of diminazene aceturate ( DIZE) , an angiotensin-converting enzyme 2 (ACE2) activator, on diabetic nephropathy (DN) rats.METHODS:Male Wistar rats (n=30) were randomly divided into normal control (NC) group, DN group and DIZE group (each group consisted of 10 rats).The rats in DN group and DIZE group were induced by intraperitoneal injection of streptozotocin at dose of 65 mg/kg.After 12 weeks, the rats in DIZE group and DN group received subcutaneous injection of DIZE (15 mg· kg -1 · d-1 ) or vehicle for 4 weeks. The samples of blood and urine were collected at week 16, and ratio of kidney weight to body weight (KW/BW), plasma glucose (GLU), 24 h urinary protein (24UP) and serum creatinine (SCr) were measured.The renal pathological changes in each group were observed by periodic acid-Schiff ( PAS) staining and immunohistochemistry .The levels of AngⅡ and Ang-(1-7) in the plasma, and TGF-β1 and VCAM-1 in the renal tissues were measured by ELISA .The mRNA and protein levels of collagen I and FN were determined by quantification real-time PCR and immunohistochemistry .The effects of DIZE on the expression of ACE2 in DN rats were determined by Western blot .RESULTS:DIZE remarkably increased the expression of ACE2 and Ang-(1-7) in DN rats.Compared with NC group , the GLU, KW/BW, 24UP, SCr, and the ex-pression of collagen I , FN, TGF-β1 and VCAM-1 in DN group and DIZE group were increased .However , after treatment of the DN rats with DIZE, these indicators were decreased except the KW/BW.The GLU showed no significant change . CONCLUSION:DIZE raised the activity of ACE2 and increased the expression of Ang-(1-7), thus alleviating fibrosis and inflammation in the kidney and having therapeutic potential for diabetic nephropathy .