Hypersomatostatinaemia in duodenal ulcer

Abstract

Abstract A sensitive and specific radioimmunoassay of serum somatostatin has been developed that overcomes the problems encountered in earlier assays of peptide disintegration and the need for prior plasma extraction, which is known to result in artifactual loss of somatostatin. In 37 normal controls, a significant positive correlation between fasting serum gastrin and somatostatin concentrations, and a significant negative correlation between pentagastrin‐stimulated maximal acid output and fasting serum somatostatin levels were observed. In the majority of 134 patients with active duodenal ulcer in whom the fasting serum somatostatin levels were normal, these relationships were absent. In the remaining 25% in whom the fasting serum somatostatin levels were abnormally raised, these relationships were retained. Following a mixed meal, circulating somatostatin levels remained unchanged in controls and patients as a group. These results suggest that: (i) in the normal state, fasting levels of circulating gastrin and somatostatin are closely related, and that acid secretion may paradoxically exert an inhibitory effect on fasting somatostatin levels; (ii) hypersomatostatinaemia identifies a subgroup of patients with duodenal ulcer in whom these relationships are retained; and (iii) somatostatin may not have a significant hormonal role in the postprandial state in man.