用于胃酸过多及胃与十二指肠溃疡。

Gastric mucin may be integrally involved in the mechanism of gastric mucosal injury caused by Helicobacter pylori leading to gastritis, peptic ulceration, and possibly gastric cancer. Gastric mucins are classified into two types based on their histochemical properties. The first is a surface mucous cell-type mucin, secreted from the surface mucous cells. The second is found in deeper portions of the mucosa and is secreted by gland mucous cells, including mucous neck cells, cardiac gland cells, and pyloric gland cells. The unique O-glycans in gastric mucin appears to function as a natural antibiotic, protecting the host from H. pylori infection. Gastric mucin may provide protection to the surface epithelium gastrointestinal tract by scavenging oxidants produced within the lumen; however, it does so at the expense of its viscoelastic properties. Both native and pronase-treated mucin effectively scavenge hydroxyl radical and that the scavenging properties are not significantly different. The effective concentration of mucin required for a 50% reduction in malondialdehyde production is 10 mg/mL for both native and pronase-treated mucin.

本品为白色至黄白色粉末或黄褐色颗粒，蛋白胨样臭味，有咸味。吸湿性强，遇水膨胀，水溶液呈灰色或乳白色，其遇热不沉淀，遇弱酸即沉淀，在溶液中能被60%以上乙醇或丙酮沉淀。遇酸较长时间作用，能分解为各种蛋白质与多糖。

方法一、乙醇沉淀法即单产工艺消化 将胃浆膜绞碎，置于耐酸夹层锅。搅拌下，按1800ml HCl:100kg胃膜比例，于pH 3-3.5，40-45℃消化4h，至消化液半透明止。双层纱布过滤除去杂质，用50%碱调pH 4-5得消化液。胃黏膜[绞碎]→胃黏膜浆[HCl, NaOH]→[pH3-3.5, 40-45℃]消化液醇沉淀 消化液搅拌下加入80%以上乙醇，含醇量达70%左右，0-5℃静置12h，收集沉淀，压干。按湿重加60%-70%乙醇2-3倍，混合均匀，洗涤1-2次，沉淀压干，搓碎，在70℃左右干燥，得粗制胃膜素。消化液[乙醇]→[0-5℃, 12h]粗制胃膜素脱脂干燥 将粗制胃膜素粉装袋，用乙醚脱脂，挥去乙醚在50℃烘干。粉碎、过80目筛得胃膜素。粗制胃膜素[乙醚]→脱脂胃膜素[粉碎]→胃膜素成品方法二、丙酮分级沉淀法消化 按每1000g胃黏膜加入18ml HCl，在pH 2.5-3, 45℃搅拌3-4h，使消化。双层纱布过滤得消化液，5℃以下冷库保存。胃黏膜浆[HCl]→[pH2.5-3, 45℃, 3-4h]消化液沉淀胃膜素 次日取消化液，常温搅拌缓加5℃以下的丙酮，使溶液相对密度达0.94-0.96，析出胃膜素，双层纱布过滤，得粗晶，70%乙醇洗涤两次，70℃干燥，乙醚脱脂两次，烘干，粉碎，得胃膜素精品。 沉淀胃蛋白酶 取沉淀胃膜素后的母液，搅拌补加5℃以下的丙酮，使相对密度达0.89-0.91, 静置4h使沉淀，虹吸去上清液回收丙酮。收集沉淀，70℃干燥，粉碎，得胃蛋白酶成品。母液[冷丙酮]→[相对密度0.89-0.91]胃蛋白酶[干燥]→胃蛋白酶成品。

Gastric mucin 是一种大的糖蛋白，保护胃肠道免受酸、蛋白酶、致病微生物和机械创伤的影响。