The effect of h(1) calponin expression on gallstone formation in pregnancy.

OBJECTIVE To explore the effect of h(1) calponin mRNA expression on the biliary tract dynamics, and investigate the molecular mechanisms of gallstone formation in pregnancy. METHODS This study was carried out in Renmin Hospital of Wuhan University, and in the Department of Molecular Biology and Biochemistry, Wuhan University School of Medicine, Wuhan, China from July to December 2004. Thirty female guinea pigs were divided randomly into 3 groups, the nonpregnant group (n=10) (group A), the 30 days of pregnancy group (n=10) (group B), and the 60 days of pregnancy group (n=10) (group C). Animal models of pregnancy were established on pregnant group guinea pigs through feeding animals with one cage according to female versus male as 4:1. The total cholesterol (TC), total bilirubin (TBiL), total bile acid (TBA) in the bile and the serum estradiol (E(2)), progesterone (Pg) levels were determined respectively. Expression levels of h(1) calponin mRNA in gallbladder smooth muscles and Oddi's Sphincter (OS) were evaluated using semiquantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS The concentration of TC, TBiL and the serum E(2) and Pg were more significantly increasing in group C than that in the other 2 groups. However, the concentration of TBA decreased gradually from group A to group C. Up-regulation of h(1) calponin gene expression was observed in the gallbladder smooth muscles in group C, but converse in OS. CONCLUSION The h(1) calponin might play an important role in inducing dysfunction of extrahepatic biliary tract, bile stasis in gallbladder and gallstone formation in pregnancy.