目的探讨胃癌及癌前期病变粘膜芳香基酰胺酶（ＡＡＤ）同工酶的表达规律，寻找癌前期病变及早期癌的标志物．方法采用本室建立的圆盘等电聚焦电泳（ＣＩＥＦ）分离１２２例各种胃病粘膜（胃癌４１例，浅表性胃炎４８例，萎缩性胃炎３０例，胃溃疡８例，其中伴肠化１９例，异型增生８例）中ＡＡＤ同工酶．以６０ｇ／Ｌ丙烯酰胺作支持递质，ｐＨ３５～５０和ｐＨ３５～１００两种载体两性电解质建立ｐＨ梯度，加匀浆液５０μｌ，阴极及阳极电极液分别用０２ｍｏｌ／ＬＮａＯＨ和０５ｍｏｌ／ＬＨ３ＰＯ４，恒压电泳（１０℃）１８ｈ后以亮氨酰β萘胺作为基质呈色．结果ＡＡＤ分为８条区带，从阳极到阴极依次命名为ＡＡＤⅠ～ＡＡＤⅧ，其中ＡＡＤⅣ主要见于胃癌（９０２％），不完全大肠型肠化（８６７％）和异型增生（７５０％）；而不伴有肠化或异型增生的良性胃病和正常胃中则未发现．ＡＡＤⅣ的阳性率与胃癌病理类型、细胞分化程度及临床分期无相关，且ＡＡＤⅣ等电点和胎盘型ＡＡＤ等电点相当．结论ＡＡＤⅣ是一种癌胚蛋白，即胃癌组织特异性同工酶，是癌前期病变及早期癌的标志物． Objective To investigate the expression patterns of mucosal aryl amidase (AAD) isoenzymes in gastric cancer and precancerous lesions, and to find precancerous lesions and early cancer markers. METHODS: 122 cases of various gastric mucosa were isolated by disc isoelectric focusing (CIEF) established in our laboratory (41 cases of gastric cancer, 48 cases of superficial gastritis, 30 cases of atrophic gastritis, and 8 cases of gastric ulcer, including intestinal metaplasia19. Cases, dysplasia in 8 cases) AAD isoenzyme. 60 g/L acrylamide was used as a supporting transmitter, pH 35～50 and pH35～100 were used to establish a pH gradient, 50 μl of the slurry was added, and the cathode and anolyte were respectively used with 02 mol /LNaOH and 05mol/LH3PO4 were electrophoresed at 10 °C for 18 h, then leucyl β-naphthylamine was used as the substrate for coloration. Results AAD was divided into 8 bands, which were named AADI-AADVIII sequentially from the anode to the cathode. AADIV was mainly found in gastric cancer (902%), incomplete intestinal type (867%) and dysplasia (75). 0%); Benign gastropathy without normal intestinal metaplasia or dysplasia was not found in normal stomach. There was no correlation between the positive rate of AADIV and pathological types, cell differentiation and clinical stages of gastric cancer, and the isoelectric points of AADIV and placental AAD were equivalent. Conclusion AADIV is a kind of oncofetal protein, which is a specific isoenzyme of gastric cancer. It is a marker of precancerous lesion and early cancer.