Salicylate- and aspirin-induced uncoupling of oxidative phosphorylation in mitochondria isolated from the mucosal membrane of the stomach.

The hypothesis that the damaging effect on the stomach mucosa of salicylic acid and its derivatives is ascribable to an uncoupling of oxidative phosphorylation has been investigated by testing of mitochondria isolated from the corpus gland area of mini-pig gastric mucosa. Mitochondria, influenced by salicylate or acetylsalicylate (0.7-5.6 mmol/l), demonstrated increased respiration rate, decreased respiratory control ratio, and decreased P/O ratio when tested in vitro. Uncoupling of oxidative phosphorylation occurred at a salicylate concentration between 3.5 and 5.6 mmol/l.