Dexamethasone inhibits arteriolar leukocyte rolling and adhesion induced by tumor necrosis factor-alpha in vivo.
OBJECTIVE
Glucocorticoids are widely used in vasculitis syndromes, however, the protective mechanisms remain to be elucidated. In this study, we wanted to examine the effect of dexamethasone on leukocyte rolling and adhesion in arterioles in vivo.


METHODS
NMRI mice were treated intrascrotally with tumor necrosis factor-alpha (TNF-alpha) for 3-4 h: Intravital microscopy was used to study leukocyte-endothelium interactions in arterioles in the cremaster muscle.


RESULTS
It was found that TNF-alpha markedly increased the number of rolling and adherent leukocytes in the arterioles. Pretreatment (2 h) with dexamethasone significantly reduced TNF-alpha-induced leukocyte rolling and adhesion. In fact, 1 mg/kg of dexamethasone decreased leukocyte rolling and adhesion by 76% and 87%, respectively.


CONCLUSIONS
These findings suggest that the beneficial effect of dexamethasone in vasculitis disorders may in part be attributable to an inhibitory impact on cytokine-induced leukocyte rolling and adhesion in arterioles.
Zhang
X W
XW
Department of Surgery, Malmö University Hospital, Lund University, Sweden.
Thorlacius
H
H
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001160:Arterioles / Q000166:cytology* / Q000187:drug effects* / Q000473:pathology; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects*; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D007274:Injections, Intraperitoneal; D007962:Leukocytes / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D018715:Microscopy, Video; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage*
D000893:Anti-Inflammatory Agents; D014409:Tumor Necrosis Factor-alpha; D003907:Dexamethasone