Butler B D, Lichtenberger L M, Hills B A
Am J Physiol. 1983 Jun;244(6):G645-51. doi: 10.1152/ajpgi.1983.244.6.G645.
Surface-active phospholipids, chemically similar to pulmonary surfactants, have been identified by thin-layer chromatography in gastric juice and on the mucosal lining of five tissues along the canine gastrointestinal tract. These included esophagus, oxyntic tissue, midduodenum, midjenunum, and midcolon. The mucosal phospholipid composition did not change appreciably along the length of the gastrointestinal tract, with the most prominent species being phosphatidylcholine (PC) (34-45%) and phosphatidylethanolamine (PE) (18-32%). The gastrointestinal mucosal surface also contained lesser amounts (5-10% each) of sphingomyelin (Sp), lysophosphatidylcholine, phosphatidylinositol (PI), and phosphatidylserine (PS) and small but detectable quantities of phosphatidylglycerol (PG) and phosphatidic acid. Both the lipid extracts of all six gastrointestinal sources as well as commercially available phospholipids identified in these samples (PC, Sp, PE, PI, PS, and PG) proved to be good boundary lubricants. Each reduced the coefficient of friction by greater than 75% between glass and carboxylated yarn when tested by a standard method for evaluating textile "sizes." The results are discussed in relation to the possible role of the surface-active molecules in imparting properties conducive to lubrication and acid protection onto the gastrointestinal epithelium.
表面活性磷脂在化学性质上与肺表面活性剂相似，已通过薄层色谱法在胃液以及犬类胃肠道五个组织的黏膜内衬中被鉴定出来。这些组织包括食管、胃体组织、十二指肠中部、空肠中部和结肠中部。胃肠道黏膜磷脂组成沿胃肠道长度并未发生明显变化，最主要的磷脂种类是磷脂酰胆碱（PC）（34 - 45%）和磷脂酰乙醇胺（PE）（18 - 32%）。胃肠道黏膜表面还含有较少含量（各占5 - 10%）的鞘磷脂（Sp）、溶血磷脂酰胆碱、磷脂酰肌醇（PI）和磷脂酰丝氨酸（PS），以及少量但可检测到的磷脂酰甘油（PG）和磷脂酸。所有六种胃肠道来源的脂质提取物以及在这些样本中鉴定出的市售磷脂（PC、Sp、PE、PI、PS和PG）均被证明是良好的边界润滑剂。当通过评估纺织品“浆料”的标准方法进行测试时，它们每一种都能使玻璃与羧化纱线之间的摩擦系数降低超过75%。本文讨论了这些表面活性分子在赋予胃肠道上皮有利于润滑和酸保护特性方面可能发挥的作用。
