Acute oral toxicity of dibenzothiophene for male CD-1 mice: LD50, lesions, and the effect of preinduction of mixed-function oxidases

The acute oral toxicity of dibenzothiophene, a component of petroleum oils, was assessed in CD-1 mice. The estimated LD50 for a single oral dose in male mice was 470 mg/kg and was lowered to 335 mg/kg by prior induction of mixed-function oxidases. Abnormal behavior that ranged from a general sluggishness to full anesthesia developed within 2 hr of treatment and resolved within 24 hr in mice that survived. Gross lesions in mice that died included pulmonary congestion and edema, mild hydrothorax, intestinal hemorrhage, and mottled livers. The major histological lesions were severe centrilobular hepatic necrosis, necrosis of lymphocytes in thymic cortices, and degenerative changes in the walls of small arteries in the lung. All mortality occurred within 72 hr of treatment.