After a brief review of the actual knowledge concerning the circulating and tissue Renin-Angiotensin System (RAS) as a unitary hormonal system, the cognitive acquisitions regarding the formation and action mechanisms of the new biologically active
angiotensins will be presented. The review of the enzymatic pathways for their synthesis and inactivation, as metabolism products of
angiotensin II (1-8), will be followed by the presentation of the main physio-pharmacological actions of
angiotensin III (2-8),
angiotensin IV (3-8) and
angiotensin (1-7). The functional involvements of the cerebral
angiotensin IV in what concerns its possible participation in the normal neurochemical processes of memory and in the neurodegenerative processes of
Alzheimer disease will be exposed, together with the vasodilating effects of
angiotensin (1-7) as counteracting factor for the constricting effects of
angiotensin II. The data concerning the bioactive fragments of
angiotensin II will be accompanied by those regarding its implication in the cardiovascular modeling and the induction of oxidative stress,
inflammation,
atherogenesis, etc. In their turn, personal researches bring new experimental evidences in favor of interactions between
angiotensin (1-7) and
angiotensin II within the rat thoracic aorta. Biphasic, dose-dependent effects were observed for
angiotensin (1-7), induced both through
nitric oxide,
kinins and
prostaglandin release for counteracting the vasoconstricting effects of
angiotensin II and the modulation of its own
vasodilator action.