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Effect of taurine on ulcerogenic response and impaired ulcer healing induced by monochloramine in rat stomachs
Author(s) -
Kato S.,
Umeda M.,
Takeeda M.,
Kanatsu K.,
Takeuchi K.
Publication year - 2002
Publication title -
alimentary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.308
H-Index - 177
eISSN - 1365-2036
pISSN - 0269-2813
DOI - 10.1046/j.1365-2036.16.s2.12.x
Subject(s) - taurine , medicine , glycine , methionine , hypochlorous acid , ischemia , oral administration , lesion , endocrinology , pharmacology , gastroenterology , amino acid , biochemistry , pathology , chemistry
Background: It is well known that neutrophil‐derived hypochlorous acid interacts with ammonia (NH 4 OH) to generate monochloramine (NH 2 Cl) and that NH 2 Cl irritates the gastric mucosa and impairs ulcer healing. Aim: To examine the effect of taurine, a hypochlorous acid scavenger, on the mucosal ulcerogenic and the impaired healing response induced by NH 2 Cl in rat stomachs, in comparison with those of methionine and glycine. Methods and results: Under anaesthesia, oral administration of NH 2 Cl (120 mmol/L) produced severe lesions in male Sprague–Dawley rat stomachs. Taurine (10–100 mg/kg) given p.o. 30 min prior to NH 2 Cl dose‐dependently prevented these lesions in response to NH 2 Cl. This action was mimicked by methionine (3–30 mg/kg) but not by glycine (10–100 mg/kg). Under urethane anaesthesia, mucosal exposure to NH 4 OH (120 mmol/L) caused a marked reduction of potential difference (PD) in the ex vivo chambered stomachs after induction of ischaemia, resulting in severe lesions. These ulcerogenic and PD responses by NH 4 OH plus ischaemia were also mitigated by taurine and methionine, but not glycine, applied to the chamber 20 min before the onset of NH 4 OH plus ischaemia. Moreover, oral administration of 100% ethanol produced severe haemorrhagic lesions in rat stomachs, all of which rapidly healed within 7 days after lesion induction. Daily administration of NH 2 Cl (20 mmol/L) significantly delayed the healing of these lesions, but recovery of this impaired healing response was obtained by concurrent administration of taurine. Both taurine and methionine showed a potent scavenging effect against NH 2 Cl in vitro . Conclusions: (1) NH 2 Cl generated either exogenously or endogenously damages the gastric mucosa and impairs the healing response; (2) taurine exerts a prophylactic effect against the deleterious effects of NH 2 Cl, mainly due to its scavenging action against NH 2 Cl; and (3) this effect of taurine may be useful for treatment of gastritis associated with Helicobacter pylori infection.