The Carcinoid Flush: Provocation by Pentagastrin and Inhibition by Somatostatin

THE carcinoid syndrome is characterized by episodes of flushing that appear to be secondary to the secretion of one or more substances by a tumor of enterochromaffin-cell origin.^{1 2 3} Flushing can be provoked pharmacologically by the administration of epinephrine,⁴ isoproterenol,⁵ ethanol,⁶ and calcium.⁷ A number of physiologic stimuli have also been reported to trigger carcinoid flushing, most notably food intake.¹ Stimulated by the observation that pentagastrin evoked flushing episodes in two patients with medullary carcinoma of the thyroid (Roberts LJ, McKenna TJ, McLean GW, et al: unpublished data), we considered the possibility that gastrin could act as an endogenous trigger of.