Alteration of the redox state of NADPH and glutathione in perfused rabbit lung by paraquat.

The glutathione and NADP+ status of perfused rabbit lung was determined both before and after perfusion with 1 mM paraquat. The pulmonary glutathione redox state was similar to that of liver, having a glutathione/glutathione disulfide ratio of about 240. This ratio was lower in lungs perfused with glucose-free medium, a condition in which NADPH probably becomes limiting. Perfusion with paraquat significantly increased the pulmonary glutathione disulfide content, particularly in the absence of glucose, resulting in a glutathione/glutathione disulfide ratio of less than 100. NADP+ levels in rabbit lung were increased approximately two-fold by perfusion with paraquat in medium containing glucose and three-fold in the absence of glucose.