Over-expression of inducible heat shock protein 70 in the gastric mucosa of partially sleep-deprived rats.
BACKGROUND
Previous findings have demonstrated increased expression of inducible heat shock protein 70 (iHSP70) in the gastric mucosa of rats exposed to partial sleep deprived (PSD). The purpose of this study was to investigate the functional role of iHSP70 and its relationship with acid secretion in the stomachs of PSD animals.


METHODS
A slowly rotating drum was used to induce PSD in male Sprague-Dawley rats with or without omeprazole treatment. Gastric mucosal samples were harvested for iHSP70 mRNA and protein analysis with RT-PCR and Western blotting, respectively. Enzyme immunoassay was used to determine plasma gastrin level and gastric acidity was measured by titration. The modulating effect of PSD on 0.6 M hydrochloric acid (HCl)-induced gastric damage was also evaluated.


RESULTS
PSD increased plasma gastrin, gastric acidity and expression of iHSP70, while significantly reducing HCl-induced gastric damage. Omeprazole administration decreased gastric acidity and reversed iHSP70 over-expression in PSD rats.


CONCLUSIONS
PSD increases gastric acidity which enhances expression of mucosal iHSP70. Over-expression of iHSP70 may be a protective homeostatic response of the stomach to stress induced by PSD and acid secretion.
Guo
J S
JS
Dept. of Pharmacology, Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.
Chau
J F L
JF
Shen
X Z
XZ
Cho
C H
CH
Luk
J M
JM
Koo
M W L
MW
D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism*; D005755:Gastrins / Q000097:blood; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009853:Omeprazole / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012892:Sleep Deprivation / Q000378:metabolism*
D000897:Anti-Ulcer Agents; D005755:Gastrins; D018840:HSP70 Heat-Shock Proteins; D012333:RNA, Messenger; D009853:Omeprazole