Prednisolone interferes with neutrophil adhesion and neutrophil mediated endothelial injury

Adhesion of leukocytes to Vascular endothelium is a crucial step in inflamm ation. This interaction may result in damage of the endothelial cells (EC). We evaluated the effects of prednisolone on adhesive interactions between human polymorphonuclear neutrophil granulocytes (PMN) and human umbilical v ein endothelial cells (HUVEC) as well as PMN mediated cytotoxicity to HUVEC (as release of (51)chromium), mediated by N-formyl-methionyl-leucyl-phenyl alanine (fMLP), lipoxin A(4) (LXA(4)), and the calcium ionophore A23187 in vitro. Prednisolone dose-dependently interfered with adhesion and cytotoxic ity induced by fMLP. Prednisolone (at 10 mu M) led to a 39%, reduction of a dhesion and an almost complete inhibition of cytotoxicity, mainly by effect s on the PMN. Prednisolone also interfered with cytotoxicity induced by LXA (4) by effects on PMN as well as on HUVEC. Adhesion and cytotoxicity induce d by the calcium ionophore A23187 was not affected in any way by prednisolo ne. Thus, in these in vitro models of vasculitis, prednisolone interferes w ith adhesive and cytotoxic interactions induced by receptor-dependent agoni sts. These protective effects of prednisolone might explain some of the ben eficial effects of glucocorticoids in the treatment of vasculitis.