Pioglitazone Induces Dysplastic Urothelial Changes in Urinary Bladder of Experimental Diabetes

OBJECTIVES: Pioglitazone (PIO) is a widely prescribed oral antidiabetic drug that has concerns regarding a potential risk of developing carcinoma of the urinary bladder. The objective of the current study was to assess this potential risk. MATERIALS AND METHODS: The potential risk of PIO-induced urinary bladder carcinoma was assessed in the current study by examining urinary bladder of rats for urothelial cytokeratin (CK) expression and proliferative activity by Ki67 immunostaining. RESULTS: Histological examination revealed dysplastic urothelial changes in PIO per se and diabetes mellitus + PIO (diabetic rats receiving PIO). In addition, a significantly (P < 0.05) decreased CK7 and CK8 expression together with a significantly increased CK20 as well as Ki67 expression was detected in the urothelial cells of groups administrated PIO, contrary to those which did not. CONCLUSION: The manifestations of urothelial dysplasia evidenced by histological examination as well as by the aberrant expression in CK and Ki67 after PIO administration add supporting evidence at cellular and experimental level to the previous clinical suspicions.