Abstract
Electronmicroscopic observations are reported on the effects of orally administered aspirin on the rat fastric mucosa to establish the cytotoxic events that occur during the early stages of the development of gastric damage induced by this drug. The results show that aspirin, apart from damaging superficial mucous cells, causes selective damage to the acid-secreting parietal cells located deep in the fundic mucosa. It is suggested that the selective accumulation of salicylates in the parietal cells may account for the specific cytotoxic actions of aspirin on these cells.