Hydrolysis of micellar phosphatidylcholine accelerates cholesterol absorption in rats and Caco-2 cells.
Lymphatic recovery of cholesterol infused into the duodenum as bile salt micelles containing phosphatidylcholine (PC) was accelerated by the co-administration of phospholipase A2 in bile and pancreatic juice diverted rats. Previously we observed that cholesterol esterase, which has the ability to hydrolyze PC, caused the same effect under a similar experimental condition (Ikeda et al., Biochim. Biophys. Acta, 1571, 34-44 (2002)). Accelerated cholesterol absorption was also observed when a part of micellar PC was replaced by lysophosphatidylcholine (LysoPC) and oleic acid. Phospholipase A2 facilitated the incorporation of micellar cholesterol into Caco-2 cells in a dose-dependent manner. There was a highly negative correlation between the incorporation of cholesterol into Caco-2 cells and the content of micellar PC remaining in the culture medium. The release of cholesterol as a monomer from bile salt micelles was enhanced when a part of micellar PC was replaced with LysoPC and oleic acid. These results strongly suggest that the release of monomer cholesterol from bile salt micelles is accelerated by hydrolysis of PC in bile salt micelles and hence that cholesterol absorption is enhanced.
Hamada
Tadateru
T
Laboratory of Nutrition Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan. tadateru@agr.kyushu-u.ac.jp
Ikeda
Ikuo
I
Takashima
Kayoko
K
Kobayashi
Makoto
M
Kodama
Yoko
Y
Inoue
Takashi
T
Matsuoka
Ryosuke
R
Imaizumi
Katsumi
K
D000818:Animals; D018938:Caco-2 Cells; D002784:Cholesterol / Q000378:metabolism* / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006868:Hydrolysis; D008208:Lymphatic System / Q000378:metabolism; D008823:Micelles; D010179:Pancreas / Q000201:enzymology; D010713:Phosphatidylcholines / Q000378:metabolism / Q000494:pharmacology*; D010741:Phospholipases A / Q000494:pharmacology; D054467:Phospholipases A2; D051381:Rats; D002787:Sterol Esterase / Q000378:metabolism; D013552:Swine
D008823:Micelles; D010713:Phosphatidylcholines; D002784:Cholesterol; D002787:Sterol Esterase; D010741:Phospholipases A; D054467:Phospholipases A2