Chicken resistance to dimethylnitrosamine acute effects on the liver: a comparative study with other species.

Dimethylnitrosamine (DMN)-induced liver damage, as measured by the increase in plasma isocitrate dehydrogenase as well as by histologic assessment of necrosis, was marked after DMN ip administration (70 mg/kg) in males of all noninbred species tested (BALB/c mouse, Sprague-Dawley rat, Syrian golden hamster, general purpose guinea pig) but not in the noninbred White Leghorn chicken. At 1 and 3 hours after DMN injection, liver DMN levels were not lower in the chicken as compared to levels in the other species. Furthermore, in all species except the chicken, significant decreases were found at 3 hours as compared to 1 hour after DMN administration. DMN metabolism to CO2 and to formaldehyde, as well as covalent binding of DMN-reactive metabolites to either proteins or nucleic acid, was measured with the use of liver slices, microsomes, and/or 9,000 X g supernatants. Results indicated that chicken liver had a very low capacity for metabolism and activation (29-3,166 times lower than comparable data in mice or hamsters).