RÉSUMÉ
This sutdy was performed to find out a LD isoenzyme pattern in neoplastic tissue of gastric carcinoma and in gastric mucosa with intestinal metaplasia, which has been known as premalignant lesion. The specimens used in this study were 18 stomachs with caarcinoma and 8 stomachs with peptic ulcer as control, and wer obtained by subtotal or total gastrectomy at Pusan National University Hsopital from Oct. 1987 to Sept. 1988. Total LD activity and its isoenzymes in body and antral mucosae and neoplastic tissue of stomach were assayed, and analysed statistically from several points of view. The results obtained were summarized as follows: 1) There was no significant difference in total LD activity between univolved body and antral mucosae of stomach with carcinoma, and between mucosa of stomach with peptic ulcer and univolved mucosa of stomach with carcinoma. 2) Total LD activity in the neoplastic tissue of gastric carcinoma was significantly higher than those of univolved body and antral mucosae of stomach with carcinoam or that of stomach with peptic ulcer, but no significant difference was observed among histological types of gastric carcinoma. 3) The uninvolved body mucosa of stomach with carcinoma or peptic ulcer showed a pattern of LD1 predominance and increas of H to M ratio, while the antral mucosa of stomach with carcinoma or peptic ulcer showed a pattern of LD3 predominance and decrease of H to M ratio. 4) The LD4 and LD5 fractions in antral mucosa with moderate to severe intestinal metaplasia were slightly increased than those of antral mucosa with nil to mild intestinal metaplasia, but did not show statistically significant difference. 5) Marked increase of LD5 fraction was found in neoplastic tissue of gastric carcinoma, and thus ratio of H to M subunit in neoplastic tissue was significantly lower, as compared with body or antral univolved mucosa of stomach. In conclusion, the neoplastic tissue of gastric carcinoma and gastric mucosa with intestinal metaplasia show substantially predominant "M" subunit as well as increased total LD activity.