Mj. Nissinen et P. Panula, HISTAMINE-STORING CELLS IN THE OXYNTIC MUCOSA OF THE RAT STOMACH - A TRANSMISSION ELECTRON-MICROSCOPIC STUDY EMPLOYING FIXATION WITH CARBODIIMIDE, The Journal of histochemistry and cytochemistry, 41(9), 1993, pp. 1405-1412
We studied the distribution of histamine (HA) immunoreactivity in endo
crine cells of the acid-producing mucosa in rat stomach with pre-embed
ding immunoelectron microscopy (IEM) using an antiserum against HA. Fo
ur fixation modifications were compared to optimize the ultrastructura
l morphology and staining pattern with the antisera produced against c
arbodiimide-conjugated HA. Fixation with 4% 1-ethyl-3(3-dimethyl-amino
propyl) carbodiimide (EDCDI) combined with both 4% paraformaldehyde an
d 0.1% glutaraldehyde gave superior results compared with EDCDI alone.
Enterochromaffin-like (ECL) cells were easily distinguished from othe
r endocrine cells in optimally fixed samples. The peroxidase endproduc
t 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-ER 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 a
nd aldehydes is suitable for IM demonstration of HA in cells. ECL cell
s form a predominant portion of endocrine cells in the oxyntic glands
and may constitute the only significant non-mast cell store of HA in r
at gastric mucosa.