Angiogenesis and hypertension: an update.

The purpose of this review is to provide a basic understanding of the important relationship between microvascular remodelling, angiogenesis and hypertension, that is, provide an overview of recent experimental and clinical evidence from anti-hypertensive and pro- and anti-angiogenic therapy with respect to hypertension and microvascular structure. Microvascular rarefaction, that is, a loss of terminal arterioles and capillaries, is found in most forms of human and experimental arterial hypertension. This further increases peripheral resistance, and aggravates hypertension and hypertension-induced target organ damage. In some cases with a genetic predisposition, hypertension is preceded by a loss of microvessels. Therefore, new therapies aimed at reversing microvascular rarefaction potentially represent candidate treatments of hypertension. The microvasculature is formed by the continuous balance between de novo angiogenesis and microvascular regression. Imbalanced angiogenesis, in addition to functional shut-off of blood flow, contributes to microvascular rarefaction. Numerous clinical trials assessing anti-angiogenic agents in cancer patients show that this therapy leads to microvascular rarefaction and causes or aggravates hypertension. The development of specific pro-angiogenic treatment to correct hypertension or ischaemic disorders, however, it is still in its infancy. On the other hand, long-term treatment by classic anti-hypertensive therapies that present vasodilator activity can correct for hypertension-associated rarefaction in man.