Primary aldosteronism (PA) and endothelial progenitor cell (EPC) bioavailability.

OBJECTIVE

Patients with primary aldosteronism (PA) experience more cardiovascular events than patients with essential hypertension matched for risk factor profile. Endothelial progenitor cells (EPC) represent a bone marrow-derived cell population implicated in vascular healing whose number correlates to the cardiovascular risk factor profile. Aldosterone has been reported to decrease EPC proliferation in rats.

DESIGN AND PATIENTS: We assessed (i) the growth characteristics of EPC from six PA patients and six matched normotensive controls; (ii) the growth characteristics of EPC treated with increasing doses of aldosterone.

MEASUREMENTS: Senescence and cell-cycle analysis of EPC from PA patients and normotensive controls and of aldosterone-treated EPC from healthy volunteers.

RESULTS

No difference was found in the senescence rate between EPC from PA patients (72.4% senescent cells) and controls (70.7%, P > 0.05). No difference was also found in the cell-cycle distribution determined by FACS (controls: 75.2% cells in G0/G1 phase; PA: 73.5%, P > 0.05). Incubation of EPC with aldosterone did not modify their senescence rate (controls: 72.4% senescent cells; aldosterone 10 nmol/l: 70.9%; aldosterone 100 nmol/l 71.6%, P > 0.05 for all comparisons) and cell-cycle distribution (controls: 73.3% cells in G0/G1 phase; aldosterone 10 nmol/l: 74.9%; aldosterone 100 nmol/l: 75.4%, P > 0.05 for all comparisons). No expression of the mineralocorticoid receptor (MR) transcript was found in EPC by RT-PCR analysis.

CONCLUSIONS

High aldosterone levels, both in PA patients and in vitro, exert no direct or indirect effect on EPC growth characteristics.