Abstract

The renin angiotensin system (RAS) is an essential regulator of renal and cardiovascular function. The components of this system are present in the circulation, organs, tissues and various cell types; and their syntheses in the organs are independent of the circulation. Understanding how the circulatory and organ RAS interact in the maintenance of the body function is knowledge that is not only key, but absolutely essential in helping us to unravel the implications of the RAS in a disease process. In this regard, this chapter aims to verify whether or not there is a consensus in the literature for the reported quantities and concentrations of Angiotensin I (Ang I), Angiotensin II (Ang II) and Angiotensin 1-7 (Ang1-7) in normal physiological states in mice, rats and humans. Because of the various methods for quantification of angiotensins, there is not presently a clear consensus for the absolute quantities of these peptides in plasma and the different tissues.