Abstract
The relationship between Helicobacter pylori colonization and the formation of stress-induced gastric mucosal injury remains unknown. Since ammonia (NH3) is known as one of the injurious factors in H. pylori-colonized gastric mucosa, the present study is designed to investigate the level of stress-induced gastric mucosal oxidative injury with or without intragastric NH3 overloading. To apply emotional stress, the communication box paradigm was used in the mouse model. Mice (C57BL/6, male) were pretreated with distilled water (responder-H2O) or 0.01% NH3 (responder-NH3) through a gastric tube once a day for a week. Emotional stress was then applied to the responder mice for 3 h per day for 3 d by watching and hearing the behavior of the sender mice subjected to electric shocks to the feet (2 mA, 10 s, 50 s interval). After the communication box protocol, the tissue MPO activity, the contents of TBA-reactive substances (TBARS), and the level of gastric mucosal HSP70 were examined. Responder-NH3 mice developed more severe gastric lesions than the responder-H2O subjects. MPO activity and TBARS contents were enhanced significantly in the responder-NH3 group compared with the responder-H2O subjects. Although the contents of HSP70 in the gastric mucosa increased in the responder-H2O group compared with the control-H2O animals, they were significantly attenuated in the responder-NH3 mice. Excess intragastric NH3 was able to enhance the formation of emotional stress-induced gastric mucosal lesions. This injury may be associated with the enhanced production of oxygen free radicals from accumulated neutrophils under the NH3-mediated cancellation of gastric mucosal cytoprotective HSP70.
| Original language | English |
|---|---|
| Pages (from-to) | 1073-1081 |
| Number of pages | 9 |
| Journal | Free Radical Biology and Medicine |
| Volume | 33 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2002 Oct 15 |
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Keywords
- Free radicals
- Heat shock protein 70
- Helicobacter pylori
- Lipid peroxide
- Myeloperoxidase
ASJC Scopus subject areas
- Medicine(all)
- Toxicology
- Clinical Biochemistry
Cite this
Ammonia aggravates stress-induced gastric mucosal oxidative injury through the cancellation of cytoprotective heat shock protein 70. / Nagahashi, Shoichi; Suzuki, Hidekazu; Miyazawa, Masaharu; Nagata, Hiroshi; Suzuki, Masayuki; Miura, Soichiro; Ishii, Hiromasa.
In: Free Radical Biology and Medicine, Vol. 33, No. 8, 15.10.2002, p. 1073-1081.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ammonia aggravates stress-induced gastric mucosal oxidative injury through the cancellation of cytoprotective heat shock protein 70
AU - Nagahashi, Shoichi
AU - Suzuki, Hidekazu
AU - Miyazawa, Masaharu
AU - Nagata, Hiroshi
AU - Suzuki, Masayuki
AU - Miura, Soichiro
AU - Ishii, Hiromasa
PY - 2002/10/15
Y1 - 2002/10/15
N2 - The relationship between Helicobacter pylori colonization and the formation of stress-induced gastric mucosal injury remains unknown. Since ammonia (NH3) is known as one of the injurious factors in H. pylori-colonized gastric mucosa, the present study is designed to investigate the level of stress-induced gastric mucosal oxidative injury with or without intragastric NH3 overloading. To apply emotional stress, the communication box paradigm was used in the mouse model. Mice (C57BL/6, male) were pretreated with distilled water (responder-H2O) or 0.01% NH3 (responder-NH3) through a gastric tube once a day for a week. Emotional stress was then applied to the responder mice for 3 h per day for 3 d by watching and hearing the behavior of the sender mice subjected to electric shocks to the feet (2 mA, 10 s, 50 s interval). After the communication box protocol, the tissue MPO activity, the contents of TBA-reactive substances (TBARS), and the level of gastric mucosal HSP70 were examined. Responder-NH3 mice developed more severe gastric lesions than the responder-H2O subjects. MPO activity and TBARS contents were enhanced significantly in the responder-NH3 group compared with the responder-H2O subjects. Although the contents of HSP70 in the gastric mucosa increased in the responder-H2O group compared with the control-H2O animals, they were significantly attenuated in the responder-NH3 mice. Excess intragastric NH3 was able to enhance the formation of emotional stress-induced gastric mucosal lesions. This injury may be associated with the enhanced production of oxygen free radicals from accumulated neutrophils under the NH3-mediated cancellation of gastric mucosal cytoprotective HSP70.
AB - The relationship between Helicobacter pylori colonization and the formation of stress-induced gastric mucosal injury remains unknown. Since ammonia (NH3) is known as one of the injurious factors in H. pylori-colonized gastric mucosa, the present study is designed to investigate the level of stress-induced gastric mucosal oxidative injury with or without intragastric NH3 overloading. To apply emotional stress, the communication box paradigm was used in the mouse model. Mice (C57BL/6, male) were pretreated with distilled water (responder-H2O) or 0.01% NH3 (responder-NH3) through a gastric tube once a day for a week. Emotional stress was then applied to the responder mice for 3 h per day for 3 d by watching and hearing the behavior of the sender mice subjected to electric shocks to the feet (2 mA, 10 s, 50 s interval). After the communication box protocol, the tissue MPO activity, the contents of TBA-reactive substances (TBARS), and the level of gastric mucosal HSP70 were examined. Responder-NH3 mice developed more severe gastric lesions than the responder-H2O subjects. MPO activity and TBARS contents were enhanced significantly in the responder-NH3 group compared with the responder-H2O subjects. Although the contents of HSP70 in the gastric mucosa increased in the responder-H2O group compared with the control-H2O animals, they were significantly attenuated in the responder-NH3 mice. Excess intragastric NH3 was able to enhance the formation of emotional stress-induced gastric mucosal lesions. This injury may be associated with the enhanced production of oxygen free radicals from accumulated neutrophils under the NH3-mediated cancellation of gastric mucosal cytoprotective HSP70.
KW - Free radicals
KW - Heat shock protein 70
KW - Helicobacter pylori
KW - Lipid peroxide
KW - Myeloperoxidase
UR - http://www.scopus.com/inward/record.url?scp=0037108205&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037108205&partnerID=8YFLogxK
U2 - 10.1016/S0891-5849(02)00998-X
DO - 10.1016/S0891-5849(02)00998-X
M3 - Article
VL - 33
SP - 1073
EP - 1081
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
SN - 0891-5849
IS - 8
ER -