Postobstructive subcellular organelle and biliary lipid composition in the rat. A selective increase in biliary lecithin output is not reflected by changes in organelle composition.
Rats infused intravenously with taurocholate shortly after relief of 48 h of biliary obstruction excrete in bile twice as much phospholipid in relation to cholesterol and bile acid as controls. In an effort to identify a subcellular compartment as the source of this biliary lipid, we examined several hepatic subcellular organelles for an increase in phospholipid to cholesterol ratio or an increase in biliary-type lecithins (16:0-18:2; 16:0-20:4) either absolute or relative to non-biliary-type lecithins (18:0-20:4; 18:0-22:6) as analyzed by high-performance liquid chromatography. Subcellular fractions studied were: three microsomal subfractions, Golgi heavy and intermediate fractions, and plasma membrane light (canaliculus-enriched) fraction. No organelle fraction from rats with biliary obstruction displayed either a significant increase in phospholipid to cholesterol ratio or a relative or absolute increase in biliary type lecithin. This suggests that biliary lipid changes are not attributable to measurable alterations in lipid composition of any anatomical compartment in the liver cells; changes are probably more related to changes in lipid turnover than to organelle total lipid pool sizes.
D000818:Animals; D001646:Bile / Q000378:metabolism*; D002779:Cholestasis / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D009940:Organoids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D010713:Phosphatidylcholines; D010743:Phospholipids; D002784:Cholesterol