Qualitative studies of gastric endocrine cells in patients treated long-term with omeprazole.

A total of 543 endoscopic biopsies (a mean of three tissue samples each) were taken from the gastric oxyntic mucosa of 122 patients suffering from reflux oesophagitis or peptic ulcer resistant to H2-receptor antagonist therapy. All were treated with omeprazole, 40 mg/day, until healing and then assigned to 20 mg/day for a mean of 13 months. Proliferative changes of endocrine cells were evaluated according to an internationally agreed classification and the paraffin sections were stained with haematoxylin-eosin and Sevier-Munger silver. Only hyperplastic (no dysplastic or neoplastic) lesions of endocrine cells were observed in 11-19% of patients examined, the incidence and severity of these lesions being unaffected by treatment. A relationship between linear and/or micronodular hyperplasia and chronic gastritis was observed.