INOCULATION OF VACA(-) AND CAGA(-) HELICOBACTER-PYLORI DELAYS GASTRIC-ULCER HEALING IN THE RAT

Background: Helicobacter pylori is associated with peptic ulcer diseas e. In the present study, the influence of VacA(-) and CagA(-) H. pylor i on gastric ulcer healing was studied in the rat. Methods: Twenty-fou r rats with acetic-acid-induced gastric ulcer were divided into two gr oups and given either vehicle (Brucella broth) or H. pylori suspension by gavage every 12 h for 7 days. The animals were killed 1 and 8 days after the last H. pylori gavage (i.e. 10 and 17 days after the induct ion of the ulcer). One hour before death, H-3-thymidine was given intr aperitoneally. Tissue samples from the stomach (including the ulcer ar ea) and the with the vehicle-treated controls, the ulcer area in H. py lori-inoculated rats was significantly larger, the epithelial apoptoti c cells in the ulcer margin and intact corpus were more numerous, whil e the cell proliferation of gastroduodenal epithelium was slightly, bu t not significantly, increased by H. pylori gavage. Conclusion: Gastri c ulcer healing was delayed after the inoculation of VacA(-) and CagA( -) H. pylori in the rat, possibly as a result of excess cell loss by a poptosis.