Lack of sodium salicylate-induced enhancement of hepatic tryptophan pyrrolase in 5 day salicylate injected rats

Single administration of sodium salicylate at doses of 400 mg/kg increased hepatic holo-tryptophan pyrrolase activity but did not produce any effect an apotryptophan pyrrolase activity in rats. Repeated administration of the drug at doses of 100 mg/kg did not alter holo-enzyme activity but decreased apo and total enzyme activity in rats killed 24 hours later. Administration of 400 mg/kg sodium salicylate to 5 day, 100 mg/kg sodium salicylate injected rats did not increase holo or apo-tryptophan pyrrolase activity. Possible role of tryptophan pyrrolase in the sodium- salicylate induced changes of brain serotonin metabolism is discussed