👤 Toshinori Kamisako

The liver and small intestine play an important role in maintaining cholesterol and bile acid balance within the body. The purpose of this study was to evaluate the effect of bile duct ligation (BDL) on the expression of intestinal and hepatic genes that are important for cholesterol and bile acid metabolism. Rats were allocated to the BDL group or the sham operation group. Blood, liver and small intestine were obtained after 24, 72 and 168 h from both groups. Serum and hepatic lipids were measured by colorimetric assays and hepatic and intestinal mRNA related to lipid metabolism was studied by reverse transcription-polymerase chain reaction (RT-PCR). Hepatic apolipoprotein (Apo) AIV, multidrug resistant protein (Mrp)2, adenosine triphosphate (ATP) binding cassette transporter (Abc)g5 and Abcg8 expression constantly decreased after BDL. Intestinal Apo AIV, Apo CIII, Mrp2, Abcg5 and Abcg8 expression remarkably decreased 24 h after BDL and recovered 72 and 168 h after BDL. Hepatic small heterodimer partner (Shp) expression did not change after BDL. Conversely, intestinal Shp expression remarkably decreased 24 h after BDL (16% of sham operation) and slightly recovered 168 h after BDL (58% of sham operation). Several intestinal mRNA expressions important for lipid (Apo AIV, Apo CIII, Abcg5 and Abcg8) and bile acid (Mrp2 and Shp) metabolism were decreased in the early phase of obstructive jaundice and the expression of these intestinal mRNA recovered in the late phase of obstructive jaundice. Show less

The purpose of this study is to evaluate the effect of bile duct ligation (BDL) on changes of lipoprotein metabolism and hepatic gene expressions that are important for cholesterol metabolism. In male rats serum, very low-density lipoprotein cholesterol, low-density lipoprotein cholesterol and apolipoproteins B and E increased after 5 days of BDL compared with those of sham operation (control) group. Serum apolipoprotein A-IV concentration in the BDL group was lower than that in the control group. In both groups, there was no difference in hepatic lipid concentrations. Hepatic mRNA expressions of scavenger receptor B1, microsomal triglyceride transfer protein (mtp), HMG-coA reductase, cholesterol 7alpha-hydroxylase and multidrug resistance gene product 2 in the BDL group were significantly higher than that in the control group. The adipocyte determination and differentiation 1 mRNA expression in the BDL group was significantly lower than that in the control group. abcg5 and abcg8 mRNA expressions were remarkably decreased in the BDL group. In conclusion, in obstructive jaundice, metabolism of lipoprotein and proteins that are important for lipid metabolism are drastically changed probably for maintaining the hepatic lipid concentration. The remarkable down-regulation of the abcg5 and abcg8 may be an adaptive change reflecting the inability of biliary cholesterol excretion. Show less