Organic anion transporter protein (OATP1B1) encoded by SLCO1B1 gene polymorphism (388A>G) & susceptibility in gallstone disease.

BACKGROUND & OBJECTIVES: Organic anion transport protein 1B1 (OATP1B1) is a major transporter protein for bile salt uptake in the enterohepatic circulation of bile salts. As the role of SLCO1B1 gene (encodes OATP1B1 or liver specific transporter-1) 388 A>G polymorphism in susceptibility towards gallstone disease is unclear the prevalence of this polymorphism in healthy north Indian population was investigated. METHODS: Peripheral venous blood of 270 unrelated northern Indian patients with symptomatic gallstone disease and 270 unrelated healthy control subjects was screened for SLCO1B1 gene 388 A>G polymorphism by PCR-RFLP method and genotyping was done on 12 per cent polyacrylamide gel. The cross-sectional data on accrual of cases and controls were collected and odds ratio with 95 per cent CI calculated as for case-control design. RESULTS: Allele frequencies of 388 G were 45 per cent in gallstone cases and 44 per cent in controls with no statistical significance. Genotype frequencies in gallstone cases and controls for, genotype AA were 30 and 32 per cent; AG: 51 and 47 per cent and GG: 16 and 21 per cent respectively. No significant association of any allele or genotype with gallstone disease was found. INTERPRETATION & CONCLUSION: Although the prevalence of SLCO1B1 gene 388A>G polymorphism in north Indian population in high, yet this polymorphism does not appear to play a significant role in susceptibility to gallstone formation.

effect of h[1] calponin expression on gallstone formation in pregnancy

To explore the effect of h1 calponin mRNA expression on the biliary tract dynamics, and investigate the molecular mechanisms of gallstone formation in pregnancy. 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 [E2], progesterone [Pg] levels were determined respectively. Expression levels of h1 calponin mRNA in gallbladder smooth muscles and Oddi's Sphincter [OS] were evaluated using semiquantitative reverse transcription polymerase chain reaction [RT-PCR]. The concentration of TC, TBiL and the serum E2 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 h1 calponin gene expression was observed in the gallbladder smooth muscles in group C, but converse in OS. The h1 calponin might play an important role in inducing dysfunction of extrahepatic biliary tract, bile stasis in gallbladder and gallstone formation in pregnancy