Polycyclic aromatic hydrocarbons decrease intracellular glutathione levels in the A20.1 murine B cell lymphoma

Previous studies in this laboratory have shown that polycyclic aromatic hydrocarbons (PAHs) inhibit lymphocyte activation and alter intracellular Ca2+ homeostasis. Other investigators have demonstrated that intracellular Ca2+ may increase in lymphocytes following exposure to chemical oxidants or ionizing radiation. Cellular oxidants produce both a rise in intracellular Ca2+ and a decrease in intracellular levels of glutathione (GSH) in numerous cells and tissues. Therefore, the purpose of the present study was to determine whether PAHs alter intracellular levels of glutathione in lymphocytes. Using different, well-established glutathione assays, it was demonstrated in the A20.1 murine B lymphoma that PAHs induce a transient decrease in intracellular glutathione. A 10-25% decrease in reduced GSH was produced by benzo(a)pyrene, 7,12-dimethylbenz(a)anthracene, benz(a)anthracene, and anthracene within 2-4 hr of exposure. Benzo(e)pyrene did not alter intracellular levels of glutathione in A20.1 cells. We conclude that glutathione depletion may contribute to cell injury in lymphocytes exposed to PAHs.