title: Increased serum concentrations of secondary bile salts during cholate feeding are due to coprophagy. A study with wild-type and Atp8b1-deficient mice.
abstract: Coprophagy (i.e., consumption of feces) is a behavior seen in rodents and other animal species. This behavior can substantially influence the enterohepatic cycling of compounds, including bile salts. Since many studies involve the feeding of rodents with bile salt supplemented diets, it is of importance to know the influence of coprophagy on bile salt composition in such studies. We compared the peripheral and portal bile salt composition of mice in conventional and metabolic cages when fed a control diet or a diet containing 0.5% cholate. We also performed these experiments with Atp8b1-deficient mice as it has been suggested that in the absence of this transporter bile salt absorption in the intestine would be increased. In mice on a control diet there is little difference in bile salt composition between conventional housing and metabolic housing. Metabolic housing led to a near complete disappearance of the low levels of dihydroxy bile salts (i.e., deoxycholate + chenodeoxycholate) in peripheral serum. In mice fed a control diet, the portal blood concentration of unconjugated dihydroxy bile salts was extremely low (<2%), but these rose to about 10% when mice were fed a cholate-supplemented diet. In metabolic cages the portal blood content of these unconjugated dihydroxy bile salts was reduced to undetectable levels. Whether housed in conventional cages or in metabolic cages, wild-type and Atp8b1-deficient mice had similar concentrations in portal blood, suggesting that intestinal bile salt absorption is not altered in Atp8b1-deficient mice.
authors.affiliation: AMC Liver Center, Academic Medical Center, Amsterdam, The Netherlands. R.P.Oude-Elferink@amc.uva.nl
authors.forename: Annemiek
authors.initials: A
authors.lastname: Groen
authors.forename: Cindy
authors.initials: C
authors.lastname: Kunne
authors.forename: Ronald P J
authors.initials: RP
authors.lastname: Oude Elferink
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics*; D000284:Administration, Oral; D000818:Animals; D001647:Bile Acids and Salts / Q000097:blood* / Q000737:chemistry; D001835:Body Weight / Q000187:drug effects; D020355:Cholates / Q000008:administration & dosage*; D003303:Coprophagia / Q000097:blood*; D005247:Feeding Behavior; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008822:Mice, Transgenic; D049294:Phospholipid Transfer Proteins; D011169:Portal Vein / Q000737:chemistry; D000637:Transaminases / Q000097:blood
chemical_list: D001647:Bile Acids and Salts; D020355:Cholates; D049294:Phospholipid Transfer Proteins; D000637:Transaminases; D000251:Adenosine Triphosphatases; C491742:Atp8b1 protein, mouse