TY - JOUR T1 - Dexamethasone inhibits secretory and cytosolic phospholipases A2 in alveolar macrophages in acute lung injury JF - European Respiratory Journal JO - Eur Respir J VL - 42 IS - Suppl 57 SP - P3863 AU - Olga Kuzniatsova Y1 - 2013/09/01 UR - http://erj.ersjournals.com/content/42/Suppl_57/P3863.abstract N2 - Alveolar macrophages (AM) synthesize secretory and cytosolic phospholipases A2 (cPLA2) – main pulmonary surfactant phospholipids metabolizing enzymes. cPLA2 activity is also important as a first step in prostaglandin biosynthesis.Purpose of research was to define phospholipases A2 activity during acute lung injury and to estimate the possibility of its correction by glucocorticoids.Methods: intratracheal administration of bleomycin to rats and radioassay of cytosolic (cPLA2) and secretory phospholipase(sPLA2) activity in AM.Results. We found increased activity of cPLA2 and sPLA2 in AM at all periods of bleomycin-induced lung injury in rats.At the first inflammatory period activity of cPLA2 was 167% (p ≤ 0.01) above control. Activity of sPLA2 exceeded the cheking level on 22%. Glucocorticoid dexamethasone (1µM) was found to significantly reduce the activity of cPLA2 (on 35%) and further to inhibit (on 27%) the activation of sPLA2 in AM during inflammatory phase of lung damage. The most prominent effect of dexamethasone on phospholipase activity was found at the period of fibroproliferation (21day), when it decreased activity of cPLA2 on 41% and sPLA2 on 48%Experiments show, that dexamethasone is an effective inhibitor of intra- and secretory phospholipases from alveolar macrophages, and can prevent the enzymatic degradation of surfactant during the lung injury. ER -