Endothelial progenitor cell impairment mediated vasodilation dysfunction via diminishing nitric oxide production in postmenopausal females.

ABSTRACT

Vascular endothelial dysfunction is the major contributing factor to hypertension. Endothelial progenitor cells (EPCs) are essential for endogenous vascular endothelial renovation. The activity and number of circulating EPCs are preserved in prehypertensive premenopausal females according to our previous research. However, the changes of EPCs in prehypertensive postmenopausal females are poorly understood, and the mechanisms responsible for the loss of the gender protection advantage of cardiovascular disease remain unexplored. In order to determine the effects of EPCs in prehypertensive postmenopausal females, the number and activity of circulating EPCs were tested in the present study. Next, the function of EPCs secreting nitric oxide (NO), vascular endothelial growth factor (VEGF) and granulocyte­macrophage colony­stimulating factor (GM­CSF), as well as their concentration in the plasma, were measured. The association between flow­mediated dilation (FMD) and EPC secretion was also assessed. Attenuation of proliferation and migration of EPCs was observed in prehypertensive patients in comparison with normotensive subjects. In addition, a reduced NO production secreted by EPCs was detected in prehypertensive patients as compared with that in normotensive patients. There was no significant difference in EPC function between postmenopausal females and age­matched males. Finally, the association between FMD and NO production was validated. Collectively, these data indicated that impaired EPCs mediated vasodilation dysfunction via decreasing NO production. Therefore, EPC function enhancement and NO level augmentation are emerging as novel therapeutic strategies for prehypertension therapy.