Increased replication of sendai virus in morphine-treated epithelial cells: evidence for the involvement of the intracellular levels of glutathione

This paper shows that morphine increases Sendai virus replication in cultur ed epithelial cells. The effect was maximal when it was added before viral infection. Morphine also reduced the intracellular level of glutathione, na mely, the oxidative and most abundant cell thiol. Altered intracellular red ox status has recently been proposed as a factor influencing viral infectio n. Support for this view was provided by our data showing that inhibition o f de novo glutathione synthesis, using L-buthionine sulfoximine, increased virus replication. These findings provide the first evidence that morphine increases the susceptibility to virus infection by altering the intracellul ar levels of glutathione. (C) 1999 International Society for Immune pharmac ology. Published by Elsevier Science Ltd.