Gastric mucosal histamine and histamine methytltransferase in patients with duodenal ulcer.

Histamine and histamine methyltransferase (HMT) have been measured in gastric mucosa from 110 patients with duodenal ulcer and 62 control subjects. Both antral and fundic mucosa had similar levels of HMT activity despite antral mucosa containing significantly less histamine. Patients with duodenal ulcer had significantly lower levels of fundic mucosal HMT activity and lower concentrations of fundic mucosal histamine than control subjects. An additional finding was that men who were cigarette smokers had significantly lower concentrations of fundic mucosal histamine (but not HMT) than non-smokers and, as there was an excess of cigarette smokers among patients with duodenal ulcer, this may be the explanation for the reduced concentrations of fundic mucosal histamine in these patients.