Helicobacter pylori infection modifies gastric and plasma ghrelin dynamics in Mongolian gerbils.
BACKGROUND
and aim: Although ghrelin, a novel growth hormone releasing peptide localised mainly in the gastric fundus, is reported not only to accelerate food passage and gastrointestinal motility but also to affect appetite and weight control, regulation of gastric ghrelin secretion under the conditions of gastric Helicobacter pylori infection is unknown. The present study was designed to investigate plasma and gastric ghrelin levels in Mongolian gerbils with H pylori colonisation of the gastric mucosa.


METHODS
Gerbils orally inoculated with H pylori were examined after inoculation. To examine preproghrelin mRNA expression in the gastric mucosa, cDNA encoding the gerbil preproghrelin and glyceraldehyde-3-phosphate dehydrogenase homologue was isolated and a quantitative reverse transcription-polymerase chain reaction system was established.


RESULTS
In gerbils showing H pylori colonisation (H pylori group), expression of preproghrelin mRNA and total ghrelin levels were significantly decreased 17 and 23 weeks later (p<0.01). Although the number of ghrelin immunoreactive cells decreased as the stomach weight increased, the gastric contents of total and active ghrelin in this group were the same as those in controls. Gastric myeloperoxidase activity showed a positive correlation with plasma ghrelin levels. On the other hand, at 17 weeks, plasma ghrelin levels were significantly increased in the H pylori group (p<0.05), suggesting a compensatory increase in secretion of the peptide at this time point.


CONCLUSIONS
The present experimental study demonstrated that gastric and plasma ghrelin dynamics are altered in response to H pylori infection.
Suzuki
H
H
Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. hsuzuki@sc.itc.keio.ac.jp
Masaoka
T
T
Hosoda
H
H
Ota
T
T
Minegishi
Y
Y
Nomura
S
S
Kangawa
K
K
Ishii
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004386:Duodenum / Q000737:chemistry / Q000378:metabolism; D005508:Food Deprivation; D005753:Gastric Mucosa / Q000737:chemistry / Q000378:metabolism*; D005849:Gerbillinae; D054439:Ghrelin; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics; D016481:Helicobacter Infections / Q000378:metabolism*; D016480:Helicobacter pylori; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007583:Jejunum / Q000737:chemistry / Q000378:metabolism; D008297:Male; D051379:Mice; D023421:Models, Animal; D008969:Molecular Sequence Data; D036361:Peptide Hormones / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D054439:Ghrelin; D036361:Peptide Hormones; D011498:Protein Precursors; D012333:RNA, Messenger; C050866:progonadoliberin I; D007987:Gonadotropin-Releasing Hormone