title: Histamine-storing cells in the oxyntic mucosa of the rat stomach: a transmission electron microscopic study employing fixation with carbodiimide.
abstract: We studied the distribution of histamine (HA) immunoreactivity in endocrine cells of the acid-producing mucosa in rat stomach with pre-embedding immunoelectron microscopy (IEM) using an antiserum against HA. Four fixation modifications were compared to optimize the ultrastructural morphology and staining pattern with the antisera produced against carbodiimide-conjugated HA. Fixation with 4% 1-ethyl-3(3-dimethyl-aminopropyl) carbodiimide (EDCDI) combined with both 4% paraformaldehyde and 0.1% glutaraldehyde gave superior results compared with EDCDI alone. Enterochromaffin-like (ECL) cells were easily distinguished from other endocrine cells in optimally fixed samples. The peroxidase end-product was distributed within the cytoplasm surrounding the vesicles of the ECL cells. ECL cells comprised about 75% of all endocrine cells, and about 90% of them were HA immunoreactive (HA-IR). No other HA-IR cell types were identified by EM in the basal half of the oxyntic region of rat gastric mucosa. The results suggest that a combination of EDCDI and aldehydes is suitable for IM demonstration of HA in cells. ECL cells from a predominant portion of endocrine cells in the oxyntic glands and may constitute the only significant non-mast cell store of HA in rat gastric mucosa.
authors.affiliation: Department of Anatomy, University of Helsinki, Finland.
authors.forename: M J
authors.initials: MJ
authors.lastname: Nissinen
authors.forename: P
authors.initials: P
authors.lastname: Panula
mesh_terms: D000818:Animals; D002234:Carbodiimides; D005404:Fixatives; D005753:Gastric Mucosa / Q000737:chemistry* / Q000166:cytology* / Q000378:metabolism; D006632:Histamine / Q000032:analysis* / Q000378:metabolism; D007106:Immune Sera; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008854:Microscopy, Electron / Q000379:methods; D016253:Microscopy, Immunoelectron; D010295:Parietal Cells, Gastric / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000737:chemistry* / Q000166:cytology*
chemical_list: D002234:Carbodiimides; D005404:Fixatives; D007106:Immune Sera; D006632:Histamine