Tl. Ching et al., STRUCTURAL CHARACTERISTICS OF HISTAMINE H-2-RECEPTOR ANTAGONISTS THATSCAVENGE HYPOCHLOROUS ACID, European journal of pharmacology. Molecular pharmacology section, 268(1), 1994, pp. 89-93
Gastric and duodenal ulcers are characterized by hypersecretion of gas
tric acid and pepsin, inflammation of the mucosa and an influx of neut
rophils. These cells can produce reactive oxygen species after stimula
tion. Particularly hydroxyl radicals and hypochlorous acid (HOCl) can
be cytotoxic and damage the gastroduodenal mucosa. It has been shown t
hat histamine H, receptor antagonists such as cimetidine, ranitidine a
nd famotidine are good hydroxyl radical scavengers. This study was und
ertaken to investigate whether these agents were able to scavenge the
cytotoxic HOCl, and if so, which part of the molecule could be respons
ible for this action. It appears that the sulfur atom in the compound
is of importance for scavenging HOCl. This finding should be taken int
o consideration in the development of new anti ulcer drugs, as HOCl is
a detrimental factor in the pathophysiology of gastroduodenal ulcers.