These studies will evaluate the chronic toxicity and carcinogenic potential of salicylazosulfapyridine (SASP) by administering the compound by gavage in corn oil vehicle, at three dose levels plus a vehicle control, to groups of F344 rats and B6C3F1 mice. A special stop exposure group of male rats will be exposed to the high dose level of chemical for 26 weeks and then help without further dosing until the end of the study. An interim sacrifice of 10 animals from the stop exposure group and vehicle control group will be sacrificed after 26 weeks of chemical exposure to evaluate the potential effects of SASP exposure on the thyroid; serum collected from these animals will be tested for T3, T4, and TSH.
