Adenomatous hyperplasia and adenomas in the lung induced by chronic feeding of butylated hydroxyanisole of Japanese house musk shrew (Suncus murinus).

A carcinogenicity study on butylated hydroxyanisole (BHA) was carried out in Japanese house musk shrews (Suncus murinus) (suncus), which have no forestomach. BHA was mixed with the basal diet and was processed into pellets. One hundred and twenty-two female and 130 male suncus were maintained with a diet containing 0, 0.5, 1.0 or 2.0% BHA for 80 weeks. All of the suncus of the 2.0% BHA groups died of bleeding in the gastrointestinal tract within 8 weeks after the commencement of the treatment. The majority of the animals in the other groups survived for greater than 52 weeks. Adenomatous hyperplasias of the lung were induced in suncus of both sexes of the 0.5 and 1.0% BHA groups at significantly higher rates than in the control groups. Lung adenomas were also induced in three suncus of the BHA groups. Pilosebaceous and musk gland tumors, mammary carcinoma, kidney hemangioma and other tumors developed in a few suncus, with no significant differences between the groups. The present study indicates that BHA induces adenomatous hyperplasia of the lung in the suncus.