TOXICOLOGY OF 1,2-DICHLOROETHANE (Ethylene Dichloride)

IV. ITS DETOXICATION BY L-CYSTINE, DL-METHIONINE AND CERTAIN OTHER SULFUR CONTAINING COMPOUNDS

¹ Laboratory of Physical Biology, National Institute of Health, U. S. Public Health Service, Bethesda, Maryland

The sulfur containing amino acids l-cystine and dl-methionine protected young rats against death from inhalation exposures to 1,2-dichloroethane. This was demonstrated when these amino acids supplemented low protein-choline deficient diets and also when they were added to normally constituted rations. Supplements of choline chloride did not give any significant protection. Nine sulfur-free amino acids were found to be nonprotective.

Other sulfur containing compounds were tested for their ability to reduce the toxicity of dichloroethane. The inorganic compounds, Na₂SO₄, NaCNS, Na₂S and Na₂S₂O₃ were ineffective. Cysteic acid, taurine and S-benzyl-l-cysteine did not protect. Protection was obtained with thiourea, thiouracil, 2-thiobarbituric, acid, '-dithiodipropionic acid and l-cysteine hydrochloride. Thiolactic acid was ineffective by mouth but afforded protection when injected intraperitoneally. It is pointed out that all of the protective compounds can furnish sulfhydryl groups.