Microvascular angiogenesis and the renin-angiotensin system.

The renin-angiotensin system is one of the major regulatory mechanisms essential for maintaining cardiovascular homeostasis. Angiotensin II is a multifunctional hormone that plays a key role in regulating this system. The importance of the renin-angiotensin system in controlling sodium homeostasis and vascular resistance is well established, however, in the past decade, much attention has been focused on the importance of angiotensin II as a regulator of microvessel density, acting through the AT1 and AT2 receptors. In this review, we discuss the connections between the renin-angiotensin system and other growth factor pathways known to be involved in pathologic and physiologic angiogenesis and rarefaction.