Hydrocortisone and dexamethasone dose-dependently stabilize mast cells derived from rat peritoneum

Background: Besides their anti-inflammatory properties, corticosteroid drugs exert anti-allergic effects. Exocytosis of mast cells is electrophysiologically detected as the increase in the whole-cell membrane capacitance (Cm). Therefore, the lack of such increase after exposure to the drugs suggests their mast cell stabilizing effects. Methods: We examined the effects of 1, 10, 100 and 200 mu M hydrocortisone or dexamethasone on the degranulation from rat peritoneal mast cells. Employing the whole-cell patch-clamp recording technique, we also tested their effects on the Cm during exocytosis. Results: At relatively lower concentrations (1,10 mu M), both hydrocortisone and dexamethasone did not significantly affect the degranulation from mast cells and the increase in the Cm induced by GTP-gamma-S. Nevertheless, at higher doses (100, 200 mu M), these drugs inhibited the degranulation from mast cells and markedly suppressed the GTP-gamma-S-induced increase in the Cm. Conclusions: Our results provided electrophysiological evidence for the first time that corticosteroid drugs, such as hydrocortisone and dexamethasone, inhibited the exocytotic process of mast cells in a dose-dependent manner. The mast cell-stabilizing effects of these drugs may be attributable to their non-genomic action, by which they exert rapid anti-allergic effects. (C) 2016 Published by Elsevier Sp. z o.o. on behalf of Institute of Pharmacology, Polish Academy of Sciences.