Beneficial effect of PGI2 on circulating endothelial cells.

Endothelial damage is an early event in atherogenesis. Recent data present evidence that the counting of circulating endothelial cells in human peripheral blood may provide reliable information about endothelial integrity. We therefore assessed the influence of PGI2 on the number of circulating endothelial cells in patients suffering from peripheral vascular disease. As cigarette smokers and patients with hyperlipoproteinemia show an increased number of circulating endothelial cells, they were excluded from this investigation. PGI2 causes a certain drop in circulating endothelial cells. In parallel, a prolongation in platelet half-life can be noted. This is most pronounced at a daily duration of infusion between 4 an 12 h. A shorter duration of PGI2 therapy is less effective in reducing circulating endothelial cells. All of the three different doses used, however, were equally effective. Placebo controls were ineffective. These findings indicate that PGI2 might exert a rather long-lasting beneficial action on endothelial integrity and the hemostatic balance.