Blood dyscrasia in calves induced by S-(dichlorovinyl)-L-cysteine.

I N THEIR SEARCH for the toxic factor in trichloroethylene-extracted soybean oil meal which can induce fatal aplastic anemia in calves,”2 cattle,3 and horses,4 McKinney et al.5 synthesized S-( dichlorovinyl)-L-cysteine (DCVC). They reported that the oral administration of this compound to calves produced leukopenia, thrombocytopenia, a relative lymphocytosis and a hemorrhagic syndrome, conditions which are also observed13 when sufficient amounts of trichloroethylene-extracted soybean oil meal are fed to calves. Although the toxic factor in this meal, which elicits this syndrome, has not been isolated and characterized, its chemical properties, insofar as they have been ascertained,57 are consistent with the view8 that it may be produced through the interaction of trichloroethylene with cysteine residues of proteins of the soybean. In conjunction with our other studies on bovine aplastic anemia, we have synthesized DCVC and confirmed its high toxicity for calves.