Lipocortin-1 distribution in bronchoalveolar lavage from healthy human lung: effect of prednisolone.
Lipocortin-1 (LC-1; annexin-1) may mediate some anti-inflammatory actions of the glucocorticoids, probably after binding to specific cell surface binding sites. We have quantified LC-1 levels in bronchoalveolar lavage (BAL) fluid and cells collected from seven healthy volunteers before and after 7 days of treatment with an oral glucocorticoid, prednisolone (30 mg/day). Extracellular BAL LC-1 was higher and cellular LC-1 was lower after prednisolone than before [extracellular: before, median 98 ng/mg albumin (range 48-350 ng/mg albumin); after, 236 ng/mg albumin (19-414 ng/mg albumin); P < 0.05. Cellular: before, 23.3 ng/10(6) cells (14.6-26.9 ng/10(6) cells); after, 18.0 ng/10(6) cells (122-268 ng/10(6) cells); P < 0.05]. The distribution of LC-1 within BAL cells ex vivo (cell surface = 25%, cytosol = 50%, membrane = 25%) was unaffected by prednisolone treatment. However, in adherent cells that had been cultured for 4 h, 70-80% of the LC-1 was on the cell surface. In summary, prednisolone appears to promote cellular release of LC-1. The difference in distribution of cellular LC-1 in BAL cells ex vivo and in vitro may reflect adherence and/or activation.
Smith
S F
SF
Department of Medicine, Charing Cross and Westminster Medical School, London, United Kingdom.
Tetley
T D
TD
Datta
A K
AK
Smith
T
T
Guz
A
A
Flower
R J
RJ
D000328:Adult; D017305:Annexin A1 / Q000276:immunology / Q000378:metabolism*; D001323:Autoantibodies / Q000032:analysis / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000166:cytology; D006801:Humans; D007958:Leukocyte Count / Q000187:drug effects; D008168:Lung / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D009994:Osmolar Concentration; D011239:Prednisolone / Q000494:pharmacology*; D012016:Reference Values; D013347:Subcellular Fractions / Q000378:metabolism; D014018:Tissue Distribution
D017305:Annexin A1; D001323:Autoantibodies; D011239:Prednisolone