The metabolism of C14 carboxyl salicylic acid in the dog and in man.

1. Metabolic studies have been carried out on dogs and human subjects with C14 carboxyl salicylic acid. 2. The urinary metabolites of salicylic acid from the dog were: 50 per cent unchanged salicylic acid, 25 per cent glycuronic acid conjugate, 10 per cent salicyluric acid and 4 to 5 per cent gentisic acid. 3. The metabolites found in human urine after salicylic acid were: 10 to 85 per cent free salicylic acid, 0 to 50 per cent salicyluric acid, 1 per cent or less of gentisic acid and 15 to 40 per cent glycuronic acid conjugates. 4. Two conjugates of salicylic acid with glycuronic acid have been identified in human urine, one of which retains a free saucyl hydroxyl group. No other glycuronate conjugates with metabolites of salicylic acid have been identified. One conjugate of salicylate with glycuronic acid has been found in dog urine.