Warfarin binding to plasma of workers exposed to toluene diisocyanate

The extent of [14]C-warfarin binding to plasma proteins was evaluated in a group of normal, healthy volunteers and in two groups of individuals occupationally exposed to toluene diisocyanate (TDI). Plasma binding was assessed by ultrafiltration after the addition of racemic [14]C-warfarin to a final concentration of 0.8 μg/ml. Chronic occupational exposure to TDI did not affect the extent of warfarin binding since warfarin free fractions (normalized to an albumin concentration of 4.5 g/dl) were 1.09 ± 0.23 (mean ± SD), 0.98 ± 0.19, and 0.97 ± 0.15 for controls and the two groups of TDI-exposed individuals, respectively.