SUBSTANCE-P SECRETION BY CARCINOID TUMORS

In 3 patients with foregut and midgut carcinoid tumours, high levels of immunoreactive substance P (ISP) were demonstrated in the general circulation, in the tumour extracts, in the tumour tissue culture medium, and in venous effluents from tumour and from metastases. In one patient studied during an attack of the carcinoid syndrome, ISP level was higher than in the basal state. Since substance P (SP) can cause flushing, hypotension, tachycardia, increased intestinal motility, and broncho-constriction, it may contribute to the pathophysiology of the carcinoid syndrome. Plasma ISP may serve as a circulating tumour marked and the levels may be used to monitor the response to therapy. © 1978 Springer-Verlag.