Integrated Treatment of Prostaglandin E1 and Angiotensin-Converting Enzyme Inhibitor in Diabetic Kidney Disease Rats: Possible Role of Antiapoptosis in Renal Tubular Epithelial Cells.

To investigate the therapeutic mechanisms underlying prostaglandin E1 (PGE1) and angiotensin-converting enzyme inhibitor (ACEI) on reducing urinary protein in diabetic kidney disease (DKD). DKD rats were established and randomly divided into four groups: PGE1 (10 μg/kg/day) (P group), ACEI (10 mg/kg/day) (A group), combination of PGE1 with ACEI treatment (P + A group), and saline treatment group (DKD group). Untreated rats were used as normal control (N group). Urinary albumin, endothelin-1 (ET-1), angiotensin II (AngII), TUNEL assay, Masson's trichrome staining, and immunohistochemistry staining for CD68 were evaluated in all groups. Ten days after treatment, urinary albumin was significantly decreased in the P and P + A groups (p < 0.01 vs. the DKD group). At the end of 8 weeks, the albumin was still significantly reduced in the P + A group (p < 0.05 vs. the A group). ET-1 and AngII were also significantly decreased in three treatment groups (p < 0.01 vs. the DKD group), especially in the P + A group. Few cells underwent apoptosis in glomerular regions in DKD rats, while amounts of apoptotic cells were seen in tubules regions. Further, apoptosis and the areas of fibrosis in tubulointerstitial were both decreased most in the P + A group compared with the DKD group. Apoptosis of renal tubular epithelial cells may participate in the development and progression of DKD in rats. Combination of PGE1 with AGEI remarkably protects renal function compared with PGE1 or ACEI monotherapy. The potential therapeutic mechanisms of PGE1 and AGEI might be via multiple targets and, at least in part, through inhibiting the apoptosis of renal tubular epithelial cells.