High expression of gastrin receptor protein in injured mucosa of Helicobacter pylori-positive gastritis.
OBJECTIVE
Gastrin is a growth factor for the gastric epithelial cells. However, it is unknown how gastric receptor (GR) expression is regulated in the gastric mucosa. We studied GR expression using a newly raised antibody and investigated the relationship between GR expression and gastritis.


METHODS
Gastric receptor expression in 63 human gastric mucosa was studied. Helicobacter pylori infection and histological gastritis status were evaluated in gastric biopsy samples. In gastric ulcer cases, additional biopsy specimens were taken from injured mucosa. Fasting sera were collected and serum gastrin level evaluated. MKN-28 cells were cultured at various pH conditions, and the change in GR expression was determined.


RESULTS
Gastric receptor expression was detected in the foveolar epithelium of the gastric mucosa, and its expression was stronger in patients infected with H. pylori. In particular, higher expression was detected in regenerating injured mucosa. There was no association between gastritis score/serum gastrin level and GR expression in H. pylori-positive cases. In MKN-28 cells, GR protein expression was lower in neutral conditions than in acidic or alkaline conditions.


CONCLUSIONS
Gastric mucosal injury with H. pylori infection destroys the pH barrier on the foveolar epithelium and may induce GR expression through pH changes.
Department of Gastroenterology and Metabolism, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
Akemi
A
Takamura
Masanori
M
Ito
Tomoyuki
T
Boda
Yoko
Y
Matsumoto
Shinji
S
Tanaka
Masaharu
M
Yoshihara
Kazuaki
K
Chayama
D000230:Adenocarcinoma / Q000378:metabolism; D000368:Aged; D001706:Biopsy; D045744:Cell Line, Tumor; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D005755:Gastrins / Q000097:blood; D005756:Gastritis / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D005786:Gene Expression Regulation; D016481:Helicobacter Infections / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D043887:Receptor, Cholecystokinin B / Q000235:genetics / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000378:metabolism
D005755:Gastrins; D043887:Receptor, Cholecystokinin B