Serotonin containing and histamine containing cells in human stomach. Identification of these cells by fluorescent microscope and electron microscope.

Paraformaldehyde (PF) treatment of epithelial cells of human stomach revealed intense yellow fluorescent granules within the cells. These granules were identified as serotonin on microspectrofluorometry. Serotonin containing cells were also identified as enterochromaffin cells (EC cells) under electron microscope and by the histochemical analysis. O-phthalaldehyde treatment (OPT) of epithelial cells in human stomach demonstrated whitish blue intracellular granules under fluorescence microscope. The cells containing these granules were identified as histamine containing cells on microspectrofluorometry, because of accordance in excitation and emission spectra with authentic histamine. Histamine-containing cells were considered to be identical to the mast cells, because of metachromatic property on toluidine blue staining and of close structural similarities under electron microscope.