Figure 1.
Extracellularly supplemented GSH inhibits ceramide generation in A549 cells. Autoradiography of ceramide in lipid extracts of A549 cells treated in the presence of regular medium supplemented with 1% serum with (A) increasing concentrations of GSH (0 to 5 mM) for 3 h or (B) 5 mM GSH for different incubation times. Incubations were terminated by washes with ice-cold PBS, and the cells were harvested with 0.05% trypsin-EDTA. Cellular lipids were extracted and assayed for ceramide by the DAG kinase assay, as described previously (5, 6). The reaction products were analyzed by TLC and autoradiography.