The effects of rabeprazole on parietal cells and enterochromaffin-like cells in rats: a comparison with omeprazole.
BACKGROUND
We investigated the effects of rabeprazole compared with those of omeprazole on enterochromaffin-like cells and parietal cells in rats.


METHODS
Rabeprazole or omeprazole was administered for 7 days by intraperitoneal injection (100 mg/kg or 20mg/kg once a day) and the serum gastrin concentration, the antral density of G cells and D cells, fundic histamine content, fundic H+, K+-ATPase mRNA level, and parietal cell morphology were determined.


RESULTS
Both rabeprazole and omeprazole inhibited gastric acid secretion and increased the intragastric pH to over 6.5, as well as causing a marked increase in the serum gastrin concentration. The serum gastrin level was lower with rabeprazole treatment than with omeprazole treatment at both doses. Also, the antral G-cell density was higher with omeprazole than with rabeprazole, while the increase in both the histamine content and the H+, K-ATPase mRNA level in the fundic mucosa was higher with omeprazole treatment at both doses, with the difference being significant at 100 mg/kg. Ultrastructural examination indicated that the stimulation of parietal cells by omeprazole was stronger than that by rabeprazole.


CONCLUSIONS
Rabeprazole treatment does not drive enterochromaffin-like cells and parietal cells as strongly as omeprazole treatment despite its potent acid suppressive effect, suggesting that it represents a new generation of proton pump inhibitors.
Tari
Akira
A
Department of Internal Medicine, Hiroshima Red Cross Hospital and Atomic Bomb Survivors Hospital, Hiroshima, Japan.
Kawano
Masanori
M
Kodama
Kanji
K
Yonei
Yoshikazu
Y
Okahara
Siro
S
Haruma
Ken
K
Sumii
Koji
K
Kajiyama
Goro
G
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D001562:Benzimidazoles / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D019861:Enterochromaffin-like Cells / Q000187:drug effects*; D005755:Gastrins / Q000032:analysis; D006632:Histamine / Q000032:analysis; D008297:Male; D023421:Models, Animal; D009853:Omeprazole / Q000494:pharmacology*; D010295:Parietal Cells, Gastric / Q000187:drug effects*; D064750:Rabeprazole; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D001562:Benzimidazoles; D005755:Gastrins; D064750:Rabeprazole; D006632:Histamine; D009853:Omeprazole