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. 1989 Jun;83(6):1936-40.
doi: 10.1172/JCI114101.

Inhibition of O2- generation by dexamethasone is mimicked by lipocortin I in alveolar macrophages

I Maridonneau-Parini  1 , M Errasfa, F Russo-Marie
Affiliations

Inhibition of O2- generation by dexamethasone is mimicked by lipocortin I in alveolar macrophages

I Maridonneau-Parini et al. J Clin Invest. 1989 Jun.

Abstract

Glucocorticoids inhibit superoxide (O2-) generation by phagocytes through a mechanism that remains unclear. We investigated this effect by using dexamethasone on guinea pig alveolar macrophages. O2- generation was induced either by the calcium ionophore A23187, a potent stimulus of phospholipase A2, or by the protein kinase C activator, phorbol myristate acetate (PMA). Dexamethasone inhibited O2- generation initiated by A23187 by 50-55%. This inhibition required: (a) more than 45 min incubation and was maximal after 2 h; (b) glucocorticoid receptor occupancy; and (c) protein synthesis. The inhibitory effect of dexamethasone could not be explained by an interaction with the respiratory burst enzyme NADPH oxidase since O2- generation was only weakly affected upon PMA stimulation. Lipocortin I, a glucocorticoid inducible and phospholipase A2 inhibitory protein, inhibited O2- generation initiated by A23187 but failed to modulate the respiratory burst activated by PMA. These results were obtained with lipocortin I purified from mouse lungs, human blood mononuclear cells, and with human recombinant lipocortin I. We propose that lipocortin I is capable of inhibiting the activation of NADPH oxidase only when membrane signal transduction involves phospholipase A2. By mimicking the effect of dexamethasone, lipocortin I may extend its potential anti-inflammatory action to the partial control of the formation of oxygen reactive species by phagocytes.

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References

    1. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350-4 - PubMed
    1. Br J Pharmacol. 1988 Aug;94(4):987-1015 - PubMed
    1. Proc Natl Acad Sci U S A. 1980 May;77(5):2533-6 - PubMed
    1. J Clin Endocrinol Metab. 1980 Sep;51(3):599-605 - PubMed
    1. Nature. 1980 Sep 11;287(5778):147-9 - PubMed

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