thrombotonin

A vasoconstrictor, liberated by blood platelets, that inhibits gastric secretion and stimulates smooth muscle; present in relatively high concentrations in some areas of the central nervous system (hypothalamus, basal ganglia), and occurring in many peripheral tissues and cells and in carcinoid tumors.

Synonym(s): 5-hydroxytryptamine, enteramine, thrombocytin, thrombotonin

[sero- + G. tonos, tone, tension, + -in]