\[Abstract\]ObjectiveTo investigate the effect of rosiglitazone (RGZ) in prevention of peritoneal fibrosis induced by peritoneal dialysis in rats.MethodsFifty SD rats were randomly divided into six groups: control group (n=5), normal saline(NS) group(n=9), model group (n=9), dimethyl sulfoxide(DMSO) group(n=9) , low-dose RGZ group (n=9) , and high-dose RGZ group (n=9). Peritoneal catheters were implanted in the last five groups, and peritoneal fibrosis models were induced in the last four groups by high-glucose peritoneal dialysate and erythromycin with rats. Animals in the low-dose RGZ and high-dose RGZ groups were treated with 1.5 mg/kg RGZ and 15 mg/kg RGZ, respectively. The one hour peritoneal equilibration test was performed and the plasma glucose and serum lipids were estimated five weeks after dialysis. The ultrafiltration volume (UF), dialysate-to-plasma urea ratio (D/Purea), and glucose reabsorption (D1/D0) were calculated. The visceral peritoneum tissues of rats were stained with hematoxylin-eosin(H-E) and Masson trichrome staining to observe the changes of peritoneal morphology. Blood vessels and leukocytes of peritoneum were quantified as n/mm2 within the histological sections with H-E staining. The expression of TGF-β1 and α-SMA in the parietal peritoneum was detected by immunohistochemistry assay. ResultsCompared with the control group, the numbers of peritoneal vessels, leukocytes, peritoneal thickness, and the expressions of TGF-β1 and α-SMA were significantly higher in the model group and DMSO group(P＜0.05). Administration of RGZ improved the above changes and significantly decreased the expression of TGF-β1 and α-SMA in the model and DMSO groups (P＜0.05). Compared with the control group, the UF and D1/D0 were significantly lower and D/Purea was significantly higher in the rest five groups (P＜0.05), and there were no significant differences between the low-dose RGZ group and the high-dose RGZ group(P＞0.05). ConclusionAdministration of rosiglitazone can effectively protect the ultrofiltration function of peritoneum during peritoneal dialysis and delay the progression of peritoneal fibrosis.