Increased adhesion and activation of polymorphonuclear neutrophil granulocytes to endothelial cells under heavy metal exposure in vitro.

Heavy metals have been implicated in the mechanisms of endothelial damage. Influences of heavy metal ions on diverse cell types have been studied using a variety of in vitro and in vivo methods. Polymorphonuclear neutrophil granulocytes (PMNs) have physiological and pathological functions, including the modulation of adhesion to and destruction of endothelial cells (ECs). PMNs were studied during interaction with human umbilical vein ECs under exposure to zinc, nickel and cobalt using an in vitro model. We studied adhesion processes with the help of a computer-controlled image-analyzing system and examined the activation of PMNs by quantification of leukotriene B4 (LTB4) release. The biphasic effects of the evaluated heavy metals on PMN-EC adhesion, with stimulation at very high and very low molar concentrations, were observed. The release of LTB4 by PMNs increased during exposure to very low metal concentrations. The initiation of these important pathogenetic mechanisms of inflammation at very low metal ion concentrations, which give no morphological changes, must be regarded as potentially significant with respect to the toxic effects of heavy metals.