This study assessed the effect of
corticosteroid treatment in the clearance of hydrothoraces in mice. Twenty-four C57BL/6 mice were divided into four groups and were injected intrapleurally with 500 microL sterilized PBS-BSA 1% to create isosmotic hydrothoraces. Two groups served as control and two groups were treated with
dexamethasone. The control groups received intraperitoneally PBS, while the
corticosteroid treatment groups received
dexamethasone (1 mg/kg), both 5 min after the induction of
hydrothorax. Control and treated animals were sacrificed 2 and 4 h after the induction of
hydrothorax, and pleural fluid volume was measured. The pleural fluid volume 2 and 4 h after the induction of hydrothoraces was significantly lower in the
dexamethasone-treated group compared to the untreated group. The rate of pleural fluid absorption 2 and 4 h after the induction of hydrothoraces was significantly higher in the
dexamethasone-treated groups. The present study demonstrated that
dexamethasone accelerates pleural fluid absorption in induced isosmotic hydrothoraces in mice. This newly reported property of
dexamethasone may partly account for the clinical observation of faster resolution of
pleural effusions when
corticosteroids are administered in patients with
pleural effusions of certain etiologies.