[Anti-angiogenesis effects of aldosterone antagonist diuretics]

Angiogenesis requires endothelial cell proliferation and their vascular rearrangement. A report of inhibiting effect of spironolactone on smooth muscle cell proliferation led us to study in vitro the effects of this drug on the endothelial cell proliferation and migration. Spironolactone (10 to 100 microM) and one of its active metabolite, canrenone (10 to 100 microM), are added to human umbilical vein endothelial cells (HUVEC). Their effect on cellular proliferation is evaluated by measuring the amount of the cellular nucleic acids using a fluorometric assay (CyQuant). Cell migration is measured using a multiwell chamber assay (Transwell). In further experiments, we investigated their effect on the capillary-like tube formation in vitro generated by HUVEC seeded in a three-dimensional biological gel (Matrigel). The VEGF (10 ng/mL) and the bFGF (10 ng/mL) were used as mitotic and cell differentiation factors. Effect on cell cycle distribution is investigated by flow cytometry analysis. Spironolactone inhibits HUVEC proliferation but canrenone does not have any significant effect. The growth promoters VEGF or bFGF do not modify inhibiting effect of spironolactone. Spironolactone (50 microM) and canrenone (50 microM) are without effect on cell migration. Capillary-like networks on Matrigel is not modified by spironolactone or canrenone. Spironolactone inhibits progression through S phase of the cell cycle. Spironolactone inhibits the proliferation of the endothelial cells in vitro but shows no effect on their migration and their rearrangement in capillary-like structures. These data should be confirmed in models of angiogenesis in vivo.