Physical-chemical behavior of dietary and biliary lipids during intestinal digestion and absorption. 2. Phase analysis and aggregation states of luminal lipids during duodenal fat digestion in healthy adult human beings

作者：Olle Hernell, Joan E. Staggers, Martin C. Carey · 发表于：Biochemistry · 年份：1990 · DOI：10.1021/bi00460a012 · 被引用次数：489 · 研究领域：Diet and metabolism studies、Fatty Acid Research and Health、Diet, Metabolism, and Disease

Following the feeding of a triacylglycerol-rich meal to healthy adult human beings, duodenal contents were aspirated for ex vivo chemical and physical-chemical analyses. The aspirates were collected during established lipid digestion and absorption into a "cocktail" of chemical inhibitors that rapidly inhibited ex vivo lipolysis. Following ultracentrifugation, the lipids separated into a floating oil layer, several interfacial layers, a "clear" or turbid "subphase", and a precipitated "pellet". By chemical and phase analyses, the floating layer was composed of oil-in-water emulsion particles with cores of triacylglycerol (TG), diacylglycerols (DG), and cholesteryl esters (CE) emulsified with a surface coat of partially ionized fatty acids (FA), monoacylglycerols (MG), diacylphosphatidylcholine (PL), and bile salts (BS). The interfacial layers contained similar emulsion particles dispersed among excess emulsifier which adopted a lamellar liquid-crystalline structure. Precipitated pellets were composed principally of emulsifying lipids, with smaller amounts of crystalline calcium soaps and BS. Relative lipid compositions of all but three subphases fell within a two-phase region of the condensed ternary phase diagram (Staggers et al., 1990, companion paper) where saturated mixed micelles composed of BS, FA "acid-soaps", MG, PL, cholesterol (Ch), and traces of DG (and TG) coexisted with unilamellar liquid-crystalline vesicles composed of the same lipids. Attempts to achieve clean...