title: Different effects of two types of H2-receptor antagonists, famotidine and roxatidine, on the mucus barrier of rat gastric mucosa.
abstract: Compared with the aggressive factors, little attention has been paid to the mucosal defensive factors in ulcer therapy, and the role of the H2-receptor antagonists in gastric mucosal protection has not been well characterized. In the present study, the effects of different types of H2-receptor antagonists (famotidine and roxatidine) on rat gastric mucus cells were investigated using both biochemical and histological methods. Each drug (famotidine, 3 mg/kg; roxatidine, 100 mg/kg) was orally administered to rats by gavage once daily for 7 days. The biosynthesis and tissue content of mucin were compared in the gastric mucosa treated with each drug. Using anti-mucin monoclonal antibodies, the mucin content and immunohistochemical localization were also compared. Both the biosynthesis and the accumulation of gastric mucin were significantly decreased in the famotidine-treated rats, but not in the roxatidine. Both the content and the immunoreactivity of surface mucus cell-derived mucin were reduced by famotidine, while they were maintained in roxatidine-treated rat stomachs. There was no difference between the groups in the content and immunoreactivity of mucous neck cell-derived mucin. H2-receptor antagonists should be classified in relation to gastric surface mucus cell function, raising the possibility of more effective ulcer therapy.
authors.affiliation: Department of Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shikama
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Iwai
authors.forename: Hajime
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kida
authors.forename: Wasaburo
authors.initials: W
authors.lastname: Koizumi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ishihara
mesh_terms: D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D015738:Famotidine / Q000494:pharmacology*; D005752:Gastric Mucins / Q000096:biosynthesis; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D008297:Male; D009093:Mucus / Q000187:drug effects; D010880:Piperidines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000897:Anti-Ulcer Agents; D005752:Gastric Mucins; D006635:Histamine H2 Antagonists; D010880:Piperidines; D015738:Famotidine; C053742:roxatidine acetate