title: The histamine release process and concomitant structural changes in rat peritoneal mast cells. In vitro study on effects of compound 48/80 and the dependence of the process on cell preparation, temperature and calcium.
abstract: Two morphologically different populations of rat peritoneal mast cells were observed in response to incubation with compound 48/80. Type 2 mast cells: cells with distinct contours exhibiting intracellular vacuoles containing altered granules and without signs of granule liberation; Type 3 mast cells: cells with indistinct countours and with varying number of granules liberated. The absence of calcium in the medium, high temperature (37 degrees C) in the presence as well as in the absence of calcium favoured type 2 versus the type 3 cells. The isolated mast cell population was less morphologically heterogeneous than the mixed cell population in response to the addition of compound 48/80. It is concluded that mast cells might release a great part of their histamine content without a concomitant liberation of the granule matrixes. The varying morphological pictures observed after incubating of mast cells with compound 48/80 is due to variable factors inherent to the experimental procedures.
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002469:Cell Separation; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000378:metabolism; D006636:Histamine Release; D008297:Male; D008407:Mast Cells / Q000166:cytology / Q000276:immunology* / Q000648:ultrastructure; D051381:Rats; D013696:Temperature; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology*
chemical_list: D003189:p-Methoxy-N-methylphenethylamine; D004533:Egtazic Acid; D002118:Calcium