Cell kinetics of mucosal atrophy in rat stomach induced by long-term administration of ammonia.
BACKGROUND
Helicobacter pylori produces ammonia in the stomach from urea. The present study was undertaken to clarify whether ammonia has an etiological role in H. pylori-associated gastric mucosal atrophy.


METHODS
Ammonia at 0.01% was administered as drinking water for 8 weeks and mucosal cell migration rate and cell proliferation were investigated in rat stomach.


RESULTS
Long-term administration of 0.01% ammonia for 4-8 weeks decreased mucosal thickness in the antrum but not in the body. Acceleration of cell migration preceded the occurrence of mucosal atrophy. Labeling indices in both antral and body mucosa significantly increased in all ammonia-treated groups, compared with those of the control group. In the antrum, the proliferative zone was significantly enlarged as mucosal atrophy developed, whereas, in body mucosa, enlargement of the proliferative zone occurred despite the absence of mucosal atrophy.


CONCLUSIONS
Ammonia at 0.01% accelerates epithelial migration, especially in the antrum, leading to mucosal atrophy. Acceleration of epithelial proliferation occurs during the development of mucosal atrophy.
Tsujii
M
M
Department of Medicine, Osaka University Medical School, Japan.
Kawano
S
S
Tsuji
S
S
Ito
T
T
Nagano
K
K
Sasaki
Y
Y
Hayashi
N
N
Fusamoto
H
H
Kamada
T
T
D000641:Ammonia / Q000494:pharmacology*; D000818:Animals; D001284:Atrophy; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D005753:Gastric Mucosa / Q000187:drug effects* / Q000473:pathology*; D005757:Gastritis, Atrophic / Q000209:etiology; D016480:Helicobacter pylori / Q000378:metabolism / Q000472:pathogenicity; D006863:Hydrogen-Ion Concentration; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D000641:Ammonia