OBJECTIVETo investigate the effect of losartan on the expression of monocyte chemoattractant protein-1 (MCP1) and transforming growth factor-β(1) (TGF-β(1)) in the kidney of rats with unilateral urethral obstruction (UUO) and evaluate protective effect of losartan against reanal interstitial fibrosis.

METHODSRat models of UUO were treated with losartan at the routine dose, high dose, and very high dose (50, 200, and 500 mg/kg daily, respectively), and saline was given to UUO model rats and rats with sham operation. At 7, 14, and 21 days, the tail cuff blood pressure (TCP), 24-h urine protein (Upro), serum Scr, BUN, K(+), percentage of renal damage and renal interstitial fibrosis (%INT) were measured in the rats. MCP1 protein in the renal tissues was detected using immunohistochemistry, and MCP1 and TGF-β(1) mRNA expressions were assayed using RT-PCR.

RESULTSAs the UUO prolonged, Upro, TCP, tubular damage, %INT, and MCP1 and TGF-β(1) mRNA expressions all increased significantly (P<0.05). High and very high doses of losartan, compared with the routine dose, obviously reversed these changes.

CONCLUSIONHigh-dose losartan can effectively control blood pressure, reduce renal damage and fibrosis, and inhibit MCP1 and TGF-β(1) expression in rats with UUO, and at a very high dose, losartan can more effectively reduce 24-h Upro than the high-dose group. High and very high doses of losartan offer better protective effect on the kidney in rats with UUO.

Animals ; Chemokine CCL2 ; metabolism ; Fibrosis ; etiology ; prevention & control ; Kidney ; metabolism ; pathology ; Losartan ; pharmacology ; Male ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism ; Ureteral Obstruction ; complications ; drug therapy

This study investigated whether tempol, an anti-oxidant, protects against renal injury by modulating phosphatidylinositol 3-kinase (PI3K)-Akt-Forkhead homeobox O (FoxO) signaling. Mice received unilateral ureteral obstruction (UUO) surgery with or without administration of tempol. We evaluated renal damage, oxidative stress and the expression of PI3K, Akt, FoxO3a and their target molecules including manganese superoxide dismutase (MnSOD), catalase, Bax, and Bcl-2 on day 3 and day 7 after UUO. Tubulointerstitial fibrosis, collagen deposition, alpha-smooth muscle actin-positive area, and F4/80-positive macrophage infiltration were significantly lower in tempol-treated mice compared with control mice. The expression of PI3K, phosphorylated Akt, and phosphorylated FoxO3a markedly decreased in tempol-treated mice compared with control mice. Tempol prominently increased the expressions of MnSOD and catalase, and decreased the production of hydrogen peroxide and lipid peroxidation in the obstructed kidneys. Significantly less apoptosis, a lower ratio of Bax to Bcl-2 expression and fewer apoptotic cells in TUNEL staining, and decreased expression of transforming growth factor-beta1 were observed in the obstructed kidneys from tempol-treated mice compared with those from control mice. Tempol attenuates oxidative stress, inflammation, and fibrosis in the obstructed kidneys of UUO mice, and the modulation of PI3K-Akt-FoxO3a signaling may be involved in this pathogenesis.
Animals ; Antioxidants/pharmacology/therapeutic use ; Collagen/metabolism ; Cyclic N-Oxides/*pharmacology/therapeutic use ; Fibrosis ; Forkhead Transcription Factors/*metabolism ; Hydrogen Peroxide/metabolism ; Kidney Diseases/drug therapy/metabolism/pathology ; Lipid Peroxidation ; Male ; Mice ; Mice, Inbred C57BL ; Oxidative Stress/drug effects ; Phosphatidylinositol 3-Kinases/*metabolism ; Phosphorylation/drug effects ; Proto-Oncogene Proteins c-akt/*metabolism ; Severity of Illness Index ; Signal Transduction/*drug effects ; Spin Labels ; Superoxide Dismutase/metabolism ; Ureteral Obstruction/complications/drug therapy/*metabolism/pathology

OBJECTIVETo investigate the possible protective effect and mechanism of ginsenoside Rb1 against oxidative damage and renal interstitial fibrosis on rats with unilateral ureteral obstruction (UUO).

METHODSIn total, 80 male rats were randomly divided into 4 groups, 20 in each group: the sham operated group (SOR), UUO group, UUO with ginsenoside Rb1 treatment group (treated with intraperitoneal injection of 50 mg/ kg daily) and UUO with Losartan treatment group (as the positive control, treated with 20 mg/kg by gastrogavage per day). The rats were randomly sacrificed on day 3, 7 and 14 after surgery, respectively. The histopathologic changes of renal interstitial tissues were observed with Masson staining. The mRNA of transforming growth factor beta 1 (TGF-beta 1), collagen I and fibronectin were reversed transcribed and quantified by Real-time PCR. Enzyme-linked immunosorbent assay was used to quantitatively detect TGF-beta 1 and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. P47phox protein expression was assessed by immunohistochemistry and Western blot analysis.

RESULTSIn the UUO model, the obstructed kidney showed typical features of progressive renal tubulointerstitial fibrosis, and the levels of TGF-beta1, collagen I and fibronectin increased (P<0.05). As compared with the UUO group, ginsennoside Rb1 significantly inhibited the interstitial fibrosis including tubular injury and collagen deposition, and decreased the levels of TGF-beta1 (P<0.05). Ginsenoside Rb1 also inhibited the heme oxygenase (HO-1) and 8-OHdG, two markers of oxidative stress (P<0.05). Moreover, ginsenoside Rb1 suppressed the expression of p47phox, a subunit of nicotinamide adeninedinucleotide phosphate (NADPH) oxidase (P<0.05).

CONCLUSIONGinsenoside Rb1 can obviously inhibit renal interstitial fibrosis in rats with UUO, its mechanism possibly via against the oxidative damage and suppressing TGF-beta1 expression.

Animals ; Deoxyguanosine ; analogs & derivatives ; urine ; Drug Evaluation, Preclinical ; Fibrosis ; genetics ; metabolism ; prevention & control ; Gene Expression Regulation ; drug effects ; Ginsenosides ; therapeutic use ; Heme Oxygenase (Decyclizing) ; metabolism ; Kidney ; drug effects ; metabolism ; pathology ; Kidney Diseases ; etiology ; genetics ; pathology ; prevention & control ; Male ; Models, Biological ; NADPH Oxidases ; genetics ; metabolism ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Saponins ; therapeutic use ; Transforming Growth Factor beta1 ; genetics ; metabolism ; Ureteral Obstruction ; complications ; drug therapy ; genetics ; metabolism