TOXICOLOGICAL EFFECTS OF BERYLLIUM ON PLATELETS AND VASCULAR ENDOTHELIUM

Although ample research has described the toxic effects of the metal b eryllium on the respiratory apparatus, less is known about its effects on the vascular apparatus, including pulmonary blood vessels, We inve stigated the in vitro effects of beryllium on endothelial vascular ade nosine diphosphatase activity and prostacyclin production in bovine ao rtic endothelium, and on nitric oxide release in isolated rabbit arter ies, Rabbit and human platelet responsiveness was also evaluated, Bery llium inhibited vascular endothelial adenosine diphosphatase activity, prostacyclin production, and nitric oxide release, thus inducing func tional alterations in vascular endothelial cells, It also induced plat elet hyperreactivity to arachidonic acid, as shown by a lowering of th e threshold of aggregating concentration and by concurrently increasin g thromboxane production, In contrast, beryllium left the response to aggregating and nonaggregating concentrations of ADP and collagen unch anged, These findings show that beryllium may impair some vascular end othelial functions and alter the interaction between platelet and endo thelial mediators. (C) 1997 Academic Press.