When small numbers of Brucella melitensis were inoculated into ABC mice, occasional hepatic granulomas without necrosis were demonstrated. The greatest multiplication of brucellae was detected in the spleens. Because it had been previously observed that ACTH or cortisone markedly accelerated the multiplication of brucellae in the livers of infected mice with destruction of liver cells, it was considered that triiodothyronine might likewise exaggerate a brucella infection by stimulating endogenous adrenal secretion. Although adrenal hypertrophy was produced, infection of mice treated with triiodothyronine resulted in severe hepatic necrosis or infarcts without the multiplication of brucellae in either the livers or spleens. The lesions were not encountered in untreated infected mice or in control mice treated with triiodothyronine. The necrosis was associated with minimal inflammatory reaction. The necrosis was not induced in mice treated with triiodothyronine and given brucella endotoxin. The precise genesis of the acute hepatic necrosis cited in these experiments remains undefined.
Triiodothyronine did not cause deaths in mice infected with Br. melitensis. The infection was neither enhanced nor suppressed.