Junker K, Svenson M, Junker S. Lithium inhibits the cytolytic glucocorticoid effect on S49 mouse lymphoma cells.
JOURNAL OF STEROID BIOCHEMISTRY 1984;
20:725-31. [PMID:
6323876 DOI:
10.1016/0022-4731(84)90076-1]
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Abstract
Cytolysis is the end point of receptor-mediated effects of glucocorticoids on S49 mouse lymphoma cells of wild-type. In the presence of 5 mM LiCl this effect of triamcinolone or dexamethasone was markedly delayed. The cytoprotective effect of Li+ against 10(-7) M triamcinolone acetonide was already manifest after 24 h of steroid incubation, and on the fifth day 50-fold more Li+-treated than control cells were viable. This effect of Li+ was not exerted through changes of the doubling time of the cells, and thus could not be ascribed to an overall reduction of protein- or RNA synthesis. Data on accumulation and effect of cyclic AMP indicated that the cytoprotective effect was independent on cyclic AMP. Furthermore Li+ did not affect the amount or affinity of glucocorticoid receptors in intact cells. By use of aqueous 2-phase partitioning and DNA-Sepharose binding of [3H]triamcinolone acetonide labelled cytosols we demonstrate that Li+ inhibits the in vitro salt-activation of the glucocorticoid-receptor complexes by 60-100%. The nuclear bound fraction of hormone-receptor complexes in intact cells at 37 degrees C was not affected by Li+. The data suggest that Li+ inhibits the cytolytic glucocorticoid effect by interacting with the hormone-receptor complexes.
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