Studies on the Reaction of Chloromethane with Human Blood

Chloromethane was shown to react with human plasma and erythrocytes. Using 14C‐CH3Cl, it was found that in plasma radioactivity was bound only by albumin. On hydrolysis the major reaction product was S‐methylcysteine; small amounts of 1‐ and 3‐methylhistidine were found. In plasma, the bound radioactivity corresponds to only 2–3% of the uptake measured using unlabelled CH3Cl, suggesting that other, unidentified volatile products are formed. In erythrocytes, approximately 40% of the uptake was bound by GSH forming S‐methylglutathione. The reaction appeared to be enzyme‐catalysed. Loss of thiol groups of plasma protein and erythrocytes and inhibition of oxygen uptake of erythrocytes could not be demonstrated. S‐Methylglutathione was neither lost from erythrocytes during separation and washing, nor was it hydrolysed. It is postulated that some of the cases of anaemia reported following exposure to chloromethane may be due to lack of erythrocyte GSH.