Effect of the interruption of enterohepatic circulation of bile acids by cholestyramine on apolipoprotein gene expression in the rat.
The aim of the study was to assess how the interruption of enterohepatic circulation may affect the regulation of apolipoprotein synthesis. For this purpose, apolipoprotein mRNA levels were measured in the liver and small intestine of male Wistar rats fed for 3 weeks diets with or without cholestyramine (5% w/w). In order to modulate intestinal lipid flux, we used diets with 2 or 10% lipid content. Cholestyramine treatment decreased plasma triglyceride and cholesterol concentrations (by 63% and 32%, respectively) in rats fed 10% corn oil containing diet but had no significant effect on plasma lipids in rats fed a low-fat diet. Plasma apo B and apo A-IV concentrations were lowered by cholestyramine treatment in both 10 and 2% oil fed groups; however plasma apo E concentration was only affected in rats receiving 10% corn oil in the diet. Cholestyramine treatment had no significant effect on plasma apo A-I concentration. Hepatic apo B, apo E and apo A-IV mRNA levels were similar among dietary groups. Cholestyramine administration caused an increase in hepatic apo A-I mRNA level only in rats fed low-fat diet. In the intestine cholestyramine treatment decreased apolipoprotein mRNA levels in jejunum but had a few effect on apolipoprotein mRNA levels in ileum. These experiments have shown that long-term decrease in the intraluminal availability of bile acids may alter not only lipid and lipoprotein metabolism but also the regulation of apolipoprotein synthesis.
Felgines
C
C
Laboratoire des Maladies Métaboliques, INRA, Theix, St Genès Champanelle, France.
Mazur
A
A
Rayssiguier
Y
Y
D000818:Animals; D001053:Apolipoproteins / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D001647:Bile Acids and Salts / Q000097:blood*; D001835:Body Weight / Q000187:drug effects; D002792:Cholestyramine Resin / Q000494:pharmacology*; D004764:Enterohepatic Circulation / Q000187:drug effects* / Q000502:physiology*; D015870:Gene Expression / Q000187:drug effects; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism; D050356:Lipid Metabolism; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000378:metabolism; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D001053:Apolipoproteins; D001647:Bile Acids and Salts; D008055:Lipids; D008074:Lipoproteins; D012333:RNA, Messenger; D002792:Cholestyramine Resin