[Is arterial hypertension a microcirculation disease?]

Capillary and arterioles rarefaction has been reported in animal models of hypertension and in essential and borderline hypertension. Moreover, young adults with a predisposition to hypertension may exhibit microvascular rarefaction suggesting that defective angiogenesis-arteriogenesis may be an etiological component of high blood pressure. Nevertheless, in other studies, VEGF plasma levels are increased in hypertensive subjects and low birth weight predicts higher blood pressure but not dermal capillary density. In fibrin gel chambers implanted in rats, angiogenesis-arteriogenesis are increased in spontaneously hypertensive rats (SHR) compared to their controls. In parallel, fibroblast growth factor synthesis is significantly increased in SHR fibrin gel chambers. Thus, excess in angio/arteriogenic factors synthesis could stimulate neovascularisation including resistive arterioles formation, which in turn increase peripheral vascular resistance and consequently trigger the hypertensive mechanism itself.