Dexamethasone inhibits respiratory glycoconjugate secretion from feline airways in vitro by the induction of lipocortin (lipomodulin) synthesis.
The effect of glucocorticoids on respiratory glycoconjugate (RGC) secretion was studied in a cat tracheal organ culture system. Dexamethasone (10(-5) to 10(-9) M) added to culture medium for 24 h caused a dose-related reversible inhibition of RCG of as much as 40% with a peak effect at 24 to 60 h after initiation of dexamethasone treatment. A monoclonal antilipocortin antibody added to the cultures blocked the inhibitory effect of dexamethasone on RGC secretion and accelerated the reversal of the dexamethasone effect after discontinuation of dexamethasone treatment. A control antibody without antilipocortin activity had no effect on RGC secretion or dexamethasone-induced inhibition of RGC secretion. Measurement of the concentration of lipocortin in airways revealed a 220% increase after treatment with dexamethasone for 24 h. We conclude that dexamethasone inhibits RGC secretion through the induction of lipocortin synthesis.
D000818:Animals; D017302:Annexins; D000911:Antibodies, Monoclonal / Q000276:immunology; D002135:Calcium-Binding Proteins; D002415:Cats; D003907:Dexamethasone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006001:Glycoconjugates / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis* / Q000276:immunology; D008297:Male; D009924:Organ Culture Techniques; D013997:Time Factors; D014132:Trachea / Q000187:drug effects* / Q000378:metabolism
D017302:Annexins; D000911:Antibodies, Monoclonal; D002135:Calcium-Binding Proteins; D006001:Glycoconjugates; D006023:Glycoproteins; C030958:lipomodulin; D003907:Dexamethasone