Immunocytochemical localization of pepsinogen I and II in the human stomach.

An immunoperoxidase method using antisera specific for PG I and PG II was developed to assess PG-containing cells in the human stomach. Fundus-chief cells contained abundant PG I and less PG II. Mucus neck cells stained more frequently with anti-PG I, while antral gland cells stained only with anti-PG II. In adenocarcinoma of the corpus, isolated glands faintly staining with anti-PG I or anti-PG II were observed. In dense tumorous tissue no anti-PG I activity could be observed, while PG II sometimes remained present in residual antral glands, even in areas of heavy tumor infiltration. Focal PG II activity was also clearly demonstrated in some antral tumor cells. The immunoperoxidase technique described is suitable for further detailed studies of normal and pathological conditions of the gastric mucosa.