title: Transintestinal and Biliary Cholesterol Secretion Both Contribute to Macrophage Reverse Cholesterol Transport in Rats-Brief Report.
abstract: Reverse cholesterol transport comprises efflux of cholesterol from macrophages and its subsequent removal from the body with the feces and thereby protects against formation of atherosclerotic plaques. Because of lack of suitable animal models that allow for evaluation of the respective contributions of biliary cholesterol secretion and transintestinal cholesterol excretion (TICE) to macrophage reverse cholesterol transport under physiological conditions, the relative importance of both pathways in this process has remained controversial.
  
  
  
  To separate cholesterol traffic via the biliary route from TICE, bile flow was mutually diverted between rats, continuously, for 3 days. Groups of 2 weight-matched rats were designated as a pair, and both rats were equipped with cannulas in the bile duct and duodenum. Bile from rat 1 was diverted to the duodenum of rat 2, whereas bile from rat 2 was rerouted to the duodenum of rat 1. Next, rat 1 was injected with [3H]cholesterol-loaded macrophages. [3H]Cholesterol secreted via the biliary route was consequently diverted to rat 2 and could thus be quantified from the feces of that rat. On the other hand, [3H]cholesterol tracer in the feces of rat 1 reflected macrophage-derived cholesterol excreted via TICE. Using this setup, we found that 63% of the label secreted with the fecal neutral sterols had travelled via the biliary route, whereas 37% was excreted via TICE.
  
  
  
  TICE and biliary cholesterol secretion contribute to macrophage reverse cholesterol transport in rats. The majority of macrophage-derived cholesterol is however excreted via the hepatobiliary route.
authors.affiliation: From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands. j.f.de.boer@umcg.nl.
authors.forename: Jan Freark
authors.initials: JF
authors.lastname: de Boer
authors.affiliation: From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Marleen
authors.initials: M
authors.lastname: Schonewille
authors.affiliation: From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Arne
authors.initials: A
authors.lastname: Dikkers
authors.affiliation: From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Koehorst
authors.affiliation: From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Rick
authors.initials: R
authors.lastname: Havinga
authors.affiliation: From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Folkert
authors.initials: F
authors.lastname: Kuipers
authors.affiliation: From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Uwe J F
authors.initials: UJ
authors.lastname: Tietge
authors.affiliation: From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Albert K
authors.initials: AK
authors.lastname: Groen
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism*; D001692:Biological Transport; D002784:Cholesterol / Q000378:metabolism*; D004386:Duodenum / Q000378:metabolism*; D005243:Feces / Q000737:chemistry; D065669:Hepatobiliary Elimination; D066237:Intestinal Elimination; D007419:Intestinal Secretions / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D023421:Models, Animal; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D002784:Cholesterol
keywords: bile; cholesterol; intestines; liver; macrophages; sterols