[A study on the mechanisms whereby apolipoprotein A-1 (apo A-1) inhibits cholesterol crystal nucleation in human gallbladder bile].
The aim of the present study was to determine the mechanisms whereby apo A-1 retards cholesterol crystal nucleation in human gallbladder bile. Ten human gallbladder bile samples were sterilely collected from patients with gallstones at surgery, subsequently applied on gel permeation chromatography to separate various lipid particles. A non-micellar fraction coeluted with apo A-1 was ultrastructurally characterized by transmission electron microscopy (TEM). As results, that fraction containing very little or no apo A-1, 400-600 A in diameter, showed rapid transformation, i.e. rouleau formation, multilamellar formation and consequently microcrystal formation, whereas those rich in apo A-1, 200-400 A in diameter, showed very little transformation for 7 days. Those data indicated that apo A-1 stabilizes non micellar fraction by forming an apo A-1 and lipid complexed particle, resulting in prolonged cholesterol crystal nucleation.
Tazuma
S
S
First Department of Internal Medicine, Hiroshima University School of Medicine, Japan.
Mizuno
S
S
Sasaki
H
H
Sagawa
H
H
Hatsushika
S
S
Tao
S
S
Yamashita
G
G
Aihara
N
N
Kajiyama
G
G
Yamamoto
M
M
D016632:Apolipoprotein A-I; D001054:Apolipoproteins A / Q000494:pharmacology / Q000502:physiology*; D001646:Bile / Q000737:chemistry; D002769:Cholelithiasis / Q000209:etiology; D002784:Cholesterol / Q000032:analysis*; D003460:Crystallization; D006801:Humans
D016632:Apolipoprotein A-I; D001054:Apolipoproteins A; D002784:Cholesterol