Expression of aquaporin-8 in the hepatocytes of pregnant rats with intrahepatic cholestasis

Abstract

To investigate the alteration on the expression levels of protein and messenger RNA (mRNA) of aquaporin-8 (AQP8) in the hepatocytes of pregnant rats with intrahepatic cholestasis induced by ethinylestradiol. A total number of 20 15-day pregnant rats were randomly divided into two groups: control group, intrahepatic cholestasis of pregnancy (ICP) group. In ICP group, rats were subcutaneously injected with ethinylestradiol (2.5 mg x kg(-1) x d(-1)) for 5 days to make the model of ICP. In control group, rats received subcutaneous injection of appropriate volume of propylene glycol for 5 days. The protein expression and subcellular localization of AQP8 in the hepatocytes of pregnant rats were detected using immunohistochemical methods. The mRNA expression of AQP8 in the hepatocytes was assayed by RT-PCR method. The model of ICP of pregnant rats was made successfully. Expressions of AQP8 protein and mRNA were detected in two groups. AQP8 protein level in ICP group was 10.8 +/- 2.4, significantly decreased than in control group 17.1 +/- 2.2 (P < 0.05). AQP8 mRNA level in ICP group was 1.07 +/- 0.11, significantly higher than in control group 0.80 +/- 0.11 (P < 0.05). Down-regulated AQP8 protein expression and up-regulated AQP8 mRNA expression in the hepatocytes of pregnant rats with intrahepatic cholestasis may contribute to the pathogenesis of ICP.