Release of serotonin from mast cells induced by N-(2-ethylhexyl)-3-hydroxybutyramide and catecholamine

A release of serotonin (5-HT), but not that of histamine, from rat peritoneal mast cells, mouse mastocytoma P-815 cells, and rabbit platelets induced by N -(2-ethylhexyl)-3-hydroxybutyramide (butoctamide) in vitro was synergistically augmented by epinephrine or norepinephrine. In the presence of 2.3 mM butoctamide and 270 μM epinephrine, the 5-HT release was optimal at pH 7.4 and 37°, and was suppressed by various enzymic and metabolic inhibitors. A viability test and microscopy indicated that, on exposure to butoctamide and epinephrine, normal mast cells were degranulated, but most of the cells still retained viability. In contrast, neoplastic mast cells showed more severe morphological alterations, and became non-viable.