Immunocytochemical localization of monoamine oxidase type B in enterochromaffin-like cells of rat oxyntic mucosa.
We used immunohistochemistry to identify the localization of monoamine oxidase type B (MAOB) in the rat oxyntic mucosa. At light microscopic levels, MAOB-immunopositive cells were mostly located in the basal half of the oxyntic mucosa. By a double-labeling immunofluorescence method, it was shown that MAOB immunoreactivity was localized in almost all of histidine decarboxylase (HDC)-positive cells. Only a few MAOB-positive cells were negative for HDC. At electron microscopic levels, immunohistochemical reaction products of MAOB were detected on the mitochondrial outer membranes in cells that showed morphological characteristics of enterochromaffin-like (ECL) cells. These findings indicate that ECL cells contain MAOB in the rat. We provide a hypothesis that MAOB is involved in the inactivation mechanism of histamine that is released from ECL cells and activates parietal cells to secrete gastric acid.
Department of Surgery, Shiga University of Medical Science, Seta, Tsukinowa-cho, Otsu, 520-2192, Shiga, Japan.
H
H
Okauchi
S
S
Nakajima
T
T
Tani
A
A
Ito
R
R
Arai
D000818:Animals; D019861:Enterochromaffin-like Cells / Q000201:enzymology*; D005753:Gastric Mucosa / Q000201:enzymology*; D006640:Histidine Decarboxylase / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism*; D008995:Monoamine Oxidase / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley
D008995:Monoamine Oxidase; D006640:Histidine Decarboxylase