Strain-dependent acute lung injury after intra-tracheal administration of a 'refined' aniline-denatured rapeseed oil: a murine model of the toxic oil syndrome?

Most attempts to reproduce the toxic oil syndrome in animals, either with case-related oils or with refined rapeseed oils, have been unsuccessful. An aniline-denatured rapeseed oil that was subsequently refined according to a protocol yielding relevant markers of "toxic oil" (oil RSO160401) had led to possibly relevant lesions following oral administration in mice. Therefore, in the present study, RSO160401 was subjected to a more extended in vivo testing. To try and maximize the response, BALB/c, DBA/2, A/J, and C57BL/6 mice were administered RSO160401 oil by a single intra-tracheal instillation (1ml/kg), with sacrifice 2 or 7 days post-exposure. Intra-tracheal administration led to a strain-dependent acute response: acute pulmonary damage in DBA/2 and A/J mice, and increases in blood eosinophilia in DBA/2 mice (6.5% vs 3.1% in controls). The pulmonary lesions regressed with time after exposure, being more complete in A/J than in DBA/2 mice. The observation of strain-dependent effects suggests that genetic susceptibility is an important factor in disease induction by the RSO160401 oil.