Dexamethasone attenuates neutrophil infiltration in the rat kidney in ischemia/reperfusion injury: The possible role of nitroxyl

Neutrophil infiltration to the tissue, which is one of the important pathog enetic factors in ischemia/ reperfusion injury, can be inhibited by glucoco rticoids. The purpose of the present study was to clarify the mechanisms by which glucocorticoids inhibit neutrophil infiltration in renal ischemia/re perfusion injury in rats. Pretreatment with dexamethasone significantly att enuated the enhanced neutrophil infiltration and expression of intercellula r adhesion molecule-1 induced by renal ischemia/reperfusion. Treatment with nitroxyl anion releaser known as Angeli's salt abolished the beneficial ef fect of dexamethasone in renal ischemia/reperfusion. Renal dysfunction and tubular damage induced by renal ischemia/reperfusion were not ameliorated b y pretreatment with dexamthasone. These results indicate that the attenuati on by dexamethasone of neutrophil infiltration and intercellular adhesion m olecule-1 expression during renal ischemia/reperfusion may be mediated by t he suppressed production of nitroxyl anion. Thus, neutrophil infiltration i n renal ischemia/reperfusion injury may be mediated, at least in part, by t he enhanced production of nitroxyl anion. (C) 2001 Elsevier Science Inc.