The Pulmonary Effects of Buthionine Sulfoximine Treatment and Glutathione Depletion in Rats

Buthionine sulfoximine (BSO), an inhibitor of de novo synthesis of glutathione (GSH), was used to deplete rats of GSH and determine the effect of treatment on antioxidant enzyme responses, lung injury, and the susceptibility to concurrent sublethal or lethal hyperoxia. In a preliminary experiment, total lung nonprotein sulfhydryl (NPSH) and GSH levels were measured at various times after single doses of BSO. The lowest concentrations were observed at 12 to 18 h. These experiments were used to establish a repeated dosing protocol for more prolonged GSH depletion. The lungs of rats treated with BSO for 4 days demonstrated markedly decreased GSH and NPSH levels (10 to 40% of control values) and glutathione peroxidase activity (45 to 60% of control values). Superoxide dismutase activities were elevated, glutathione reductase activity was slightly elevated, and catalase activity was unchanged. These changes were dose-responsive. The lungs of treated rats were grossly and microscopically normal. BSO treatment o...