PRODUCTION AND CHARACTERIZATION OF SPECIFIC ANTIBODIES - UTILIZATION TO PREDICT ORGAN-SELECTIVE AND SPECIES-SELECTIVE PNEUMOTOXICITY OF 3-METHYLINDOLE

3-methylindole (3MI) selectively causes damage to pulmonary tissues; t he species-selective order is goats, rats, and rabbits, with rabbits s ustaining the least damage. 3MI is bioactivated to toxic intermediates by cytochrome P450 enzymes. Covalent binding of the electrophilic 3-m ethyleneindolenine intermediate to proteins is a likely mechanism of 3 MI-mediated lung damage. Polyclonal antibodies were developed to thioe ther adducts of 3-methyleneindolenine and were shown by competitive en zyme-linked immunosorbent assay (ELISA) to be highly selective for the detection of 3MI adducts. Rabbits, rats, and goats were treated with 350, 400, and 15 mg/kg 3MI, respectively. The lungs, liver, and kidney s of each animal were collected 24 hr later and tissue fractions were analyzed by ELISA, Lung tissue fractions from goat (pellet, cytosol, a nd microsomes) had greater immunoreactivity than those from rat. Immun oreactivity in rat tissues was greater than that in rabbit tissues. In all of the animals, lung had greater immunoreactivity than kidney, an d kidney had greater reactivity than liver. These studies demonstrate that thioether adducts of 3MI with proteins can be detected specifical ly by these antisera, and the adducts are precisely correlated to spec ies and tissue susceptibility of 3MI. In addition, human lung and Live r samples were moderately immunoreactive. Therefore, humans form adduc ts of 3MI in these tissues and are predicted to be susceptible to 3MI- mediated toxicity. (C) 1997 Academic Press.