title: Induction of granulopoiesis of mastocytoma cells: ultrastructural and cytochemical studies on production of serotonin in a cultured mouse mastocytoma cell line.
abstract: Electron microscopic observations of an originally established mouse mastocytoma cell line (BSP-MST-2) revealed that the cytoplasm of many of the MST-2 cells contained small and low osmiophilic granules and a few mature electron-dense granules. Fluorescent- and immuno-histochemical examinations also suggested the immaturity of granules as the cytoplasmic reaction for serotonin (5-HT) was weak. Induction of further maturation of granules was investigated by administration of various chemical agents. Among the chemicals examined, sodium butyrate and hydrocortisone were effective. In the presence of 1 mM sodium butyrate for 24 h, the cytoplasmic granules contained an abundant dense matrix. MST-2 cells incubated with hydrocortisone at 5 micrograms/ml for 24 h showed a somewhat different granulopoietic pattern from those incubated with sodium butyrate, including numerous electron-dense progranules. Fluorescent- and immuno-histochemical studies showed increased reactions of cytoplasmic 5-HT of both butyrate- and hydrocortisone-treated MST-2 cells. The specificity of these morphological and cytochemical changes was confirmed by treatment with reserpine, a drug which depletes cellular 5-HT; electron-dense materials were virtually diminished and cytochemical reactions were significantly decreased. The mode of induced production of 5-HT in mastocytoma granules is discussed, in relation to mastocyte differentiation.
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D006098:Granulocytes / Q000502:physiology*; D006410:Hematopoiesis; D006651:Histocytochemistry; D012515:Mast-Cell Sarcoma / Q000378:metabolism* / Q000503:physiopathology / Q000648:ultrastructure; D051379:Mice; D012701:Serotonin / Q000096:biosynthesis*
chemical_list: D012701:Serotonin