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标题：Effects of docosahexaenoic acid on annular lipid fluidity of the rat bile canalicular plasma membrane
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作者：Michio Hashimoto ; M. Shahdat Hossain ; Toshio Shimada 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2001
卷号：42
期号：7
页码：1160-1168
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：The role of docosahexaenoic acid (DHA) in the fluidity of the annular lipid regions and their associated membrane-bound proteins is still not as well understood as that in the global (bulk) lipid regions. We therefore studied the effects of dietary DHA on the relationship between annular and global lipid fluidity and membrane-bound enzymes such as 5′-nucleotidase and Mg²⁺-ATPase in the rat bile canalicular membrane. Dietary DHA caused significant increases in 5′-nucleotidase and Mg²⁺-ATPase activity and in global and annular lipid fluidity, a higher increase in fluidity in the annular lipids than the global lipids, and a decrease in the cholesterol-to-phospholipid molar ratio in the canalicular membrane. Plasma total cholesterol and LDL cholesterol decreased, and fecal cholesterol increased in the DHA-fed rats. No changes were observed in oxidative markers, but glutathione peroxidase increased in the liver with DHA feeding. Annular lipid fluidity, but not global lipid fluidity, correlated remarkably well with DHA, synchronously with the activities of 5′-nucleotidase and Mg²⁺-ATPase. The data indicate that the DHA-induced increase in annular lipid fluidity is responsible for the increases observed in the enzyme activity. We therefore concluded that the increased activity of membrane-bound enzymes and transporters induced by DHA and the concomitant increase in annular lipid fluidity comprise one of the mechanisms involved in DHA-induced clearance of plasma cholesterol. —Hashimoto, M., M. S. Hossain, T. Shimada, H. Yamasaki, Y. Fujii, and O. Shido. Effects of docosahexaenoic acid on annular lipid fluidity of the rat bile canalicular plasma membrane. J. Lipid Res. 2001. 42: 1160–1168.
关键词：membrane-bound enzymes ; antioxidative enzymes ; membrane lipid ; plasma cholesterol ; pyrene