Abstract
Twenty typical mid-gut carcinoid tumours were examined for the presence of gastrin immuno-reactivity to antisera specific to the C-terminal pentapeptide or to the mid-portion of gastrin-17. Pentagastrin immuno-reactivity was found in seven cases, and in one of these reactivity to antiserum against the mid-portion of gastrin-17 was also observed. The results are in accordance with the previous observation that argyrophil tumour cells are present in mid-gut carcinoid tumours and may explain why peptic ulcer disease is sometimes seen in association with the carcinoid syndrome.