Gastrin sensitivity in duodenal ulcer.

The sensitivity to pentagastrin measured as D50C, the dose required for half maximal acid output (MAO) corrected for basal acid output, in 200 patients with active duodenal ulcer was significantly (p less than 0.001) higher than that in 36 age- and sex-matched controls, and was above the normal limit in 27% of the patients. The distribution of D50C was significantly different between early onset and late onset patients, defined as patients whose ulcer symptoms started at respectively age less than or equal to 30 years and age greater than 30 years. Among patients whose MAO/kg body weight was within 2 SD of the normal mean as established previously in 100 normal subjects, gastrin sensitivity was significantly greater in late onset than in early onset patients, and in those who were positive than in those who were negative for familial ulcer dyspepsia. Among patients with abnormally large MAO, the reverse was true, gastrin sensitivity being greater in early rather than in late onset patients, and in patients negative rather than in those positive for familial ulcer dyspepsia. These findings suggest that gastrin hypersensitivity is a distinct physiological abnormality in duodenal ulcer, the increased gastrin sensitivity in some patients with normal MAO has a genetic basis but the lateness in onset of their disease also suggests an environmental origin, and the increased gastrin sensitivity in some patients with abnormally large MAO is related to environmental factors encountered early in life.