Ruthenium red-sensitive cation channels, but not calcitonin gene-related peptide or substance P-mediated mechanisms, protect duodenal villi against acid-induced damage

Felix W. Leung, Fumihiro Iwata, John Kao, Kyoji Seno, Makoto Itoh, Joseph Leung

Research output: Contribution to journalArticle

3 Scopus citations


Intestinal mucosal capsaicin-sensitive afferent nerves mediate, in part, the protective mesenteric hyperemia after intraduodenal acidification. Mechanisms associated the sensory neuropeptides, e.g. calcitonin gene-related peptide (CGRP), substance P, and ruthenium red-sensitive cation channels contribute to acid-induced mesenteric hyperemia, but whether they play a role in protection against acid-induced duodenal villous damage is not known. We tested the hypothesis that in doses that attenuate acid-induced hyperemia, inhibitors of these mechanisms will exacerbate acid-induced duodenal villous damage. Intravenous vehicle, specific receptor antagonists of CGRP (CGRP8-37), substance P (CP 96345), intraduodenal ruthenium red or vehicle was administered, followed by intraduodenal perfusion with 0.1 N HCl. Duodenal tissue was processed for hematoxylin and eosin staining. Villous damage was scored by blinded observers. Deep villous injury was significantly increased after treatment with ruthenium red, but not with CGRP8-37 or CP 96345. These findings support the hypothesis that ruthenium red-sensitive cation channels, but not neuropeptides associated with intestinal mucosal afferent nerves, are involved in the acid-sensing mechanism which mediates the protection against acid-induced duodenal villous damage.

Original languageEnglish (US)
Pages (from-to)2617-2624
Number of pages8
JournalLife Sciences
Issue number22
StatePublished - Oct 18 2002
Externally publishedYes



  • Acid-induced duodenal villous injury
  • CGRP
  • Ruthenium red
  • Substance P

ASJC Scopus subject areas

  • Pharmacology

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