[Macroscopic and histometric studies on the experimental acetic-acid ulcer of the rat stomach]

This work is concerned with the formation, development and healing of a chronic experimental ulcer produced by the injection of a 30 percent solution of acetic acid in the submucosa of the rat stomach. The healing process of the induced lesions was assessed by comparing their diameters with macroscopic as well as microscopic measuring techniques. Observations were made at 17 different time points from 5 minutes to 245 days after induction on groups of 5 to 10 rats each. The macroscopically and microscopically determined values agreed well for the period from 3 hours to 12 days. However, at the earlier and later time points differences occurred because of the histological changes peripheral to the lesions and increased enlargement of the regenerating area respectively. Healing proceeded slowly. On day 147 and 245 the ulcerated lesion was still detectable in one out of 10 animals. An exacerbation of ulcers as reported by others did not seem to be present.