Interaction of formaldehyde with glutathione in the isolated/ventilated perfused lung and the isolated perfused liver.

Abstract

The interaction of formaldehyde (CH2O) with reduced glutathione (GSH) was evaluated in aqueous solution and in isolated perfused lungs and livers. Addition of CH2O (0-4.9 mM) to a solution of 0.17 mM GSH in 2 mM EDTA, pH 7.4, resulted in a time- and concentration-dependent depletion of GSH. Perfusion of livers with fortified Krebs-Ringer bicarbonate buffer containing 0.3-4.9 mM CH2O resulted in a dose-dependent depletion of GSH. Perfusion of isolated ventilated lungs with perfusate containing 4.9 mM CH2O resulted in a depletion of GSH to 75% of controls. However, lower concentrations of CH2O in the lung perfusate did not result in depletion of GSH. These results demonstrate that exposure to CH2O in aqueous solution or in the perfused lung and liver is capable of depleting endogenous GSH. However, the concentrations of CH2O required to yield a significant depletion of endogenous GSH exceed those encountered in vivo. Thus, it is unlikely that depletion of GSH by CH2O is a causal factor in formaldehyde-induced toxicity.