title: Stimulation by epinephrine of histamine synthesis by rat peritoneal fluid mast cells in vitro.
abstract: In vitro exposure of mast but not of other cells of rat peritoneal fluid to epinephrine leads, within 1 min, to progressing levels of histamine in both fluid and sedimentable phases of the incubates, which present no increase in their free/total histamine ratio. Histamine increase was blocked by alpha-fluoromethyl histidine (alpha FMH), acting after a significant lag period. When compared with controls under the electron microscope, epinephrine-treated mast cells show less electron-dense, swollen intracellular granules, apparent maintenance of cell membrane continuity and an apparent decrease of peripheral finger-like projections. Histamine accumulation by epinephrine-treated mast cells may be the result of an enhanced ability of pre-formed mast cell histidine decarboxylase to attack its cell-borne substrate, consequent to an unfolding of the cell membrane during cell tumefaction evoked by epinephrine.
mesh_terms: D000818:Animals; D004837:Epinephrine / Q000494:pharmacology*; D005260:Female; D006632:Histamine / Q000096:biosynthesis*; D006636:Histamine Release / Q000187:drug effects*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology* / Q000648:ultrastructure; D008762:Methylhistidines / Q000494:pharmacology; D008854:Microscopy, Electron; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D008762:Methylhistidines; C028309:alpha-fluoromethylhistidine; D006632:Histamine; D004837:Epinephrine