We examined whether a single inoculation of Helicobacter pylori can colonize the stomachs of ulcerated rats and delay their healing and whether an
antibiotic drug and
acid pump inhibitors can enhance the
ulcer healing in infected rats.
Ulcers were produced by a submucosal injection of
acetic acid solution into the gastric wall. Helicobacter pylori (ATCC-43504) was inoculated into rats with and without
gastric ulcers. The animals were killed 2, 4, 6, 8 or 10 weeks after the inoculation and the ulcerated area and H. pylori viability were determined. Each test
drug and their combination was administered for 1 or 2 weeks after H. pylori inoculation. Helicobacter pylori could not colonize the stomachs of normal rats, but could colonize stomachs with
ulcers for 10 weeks at an incidence of >80%.
Spontaneous healing of
gastric ulcers was delayed by H. pylori
infection during these 10 weeks. Daily treatment with
clarithromycin significantly and dose-dependently delayed
ulcer healing in infected rats. Both
omeprazole and
leminoprazole significantly enhanced
ulcer healing and inhibited the
clarithromycin-delayed
ulcer healing. We conclude that: (i) H. pylori can colonize rat stomachs with
ulcers and delay
ulcer healing; (ii)
clarithromycin delays
ulcer healing in H. pylori-infected rats; and (iii)
acid pump inhibitors inhibited the
clarithromycin-delayed
ulcer healing.