Il sistema renina-angiotensina: aspetti filogenetici

The renin-angiotensin system (RAS) is the most important physiological system controlling blood pressure and maintaining the extracellular volume and osmotic homeostasis in vertebrates. It works via the kidney control of water and sodium excretion and via the direct and sympathetic-mediated regulation of arteriolar constriction. The phylogenetic analysis of RAS development shows that important components were already present in some invertebrates living in salt water, but they were not structured and interconnected. It was only with the first chordates that a structured system appeared, as in the case of lamprey. This review provides information about the phylogenetic appearance and structure of the different RAS components (angiotensinogen, renin, angiotensins and receptors), and about their function and regulation in non mammalian veterbrates. The RAS functions that have been conserved throughout evolution, and the physiological significance of RAS are also highlighted.