Multiple endocrine neoplasia type II: the role of gastrointestinal humoral factors in calcitonin release following alcohol and pentagastrin stimulation.

Familial medullary carcinoma of thyroid (MCT) can be diagnosed early by measuring stimulated plasma calcitonin following provocation with 50 ml of oral whisky, or 0.5 microgram kg-1 i.v. pentagastrin. The calcitonin release, however, can be variable following both stimuli. To determine whether a humoral mechanism might be involved in mediating this calcitonin release, nine gut peptides, histamine, alcohol, calcium, and calcitonin, were measured in the plasma of eight patients whose family was affected by multiple endocrine neoplasia Type II syndrome. Pentagastrin produced significant rises in plasma calcitonin, histamine and pancreatic polypeptide. Whisky produced a variable rise in plasma alcohol, but significant rises in plasma calcitonin, histamine and pancreatic polypeptide as well as insulin (P less than 0.05). This study suggests that histamine may be the mediator of calcitonin release following provocation by either pentagastrin or alcohol. Histamine infusion requires evaluation as a screening test for MCT in MEN II syndrome.