[Active metabolites derived from angiotensin II].
It has been recently shown that angiotensin II (Ang II) is not the only active peptide of the renin-angiotensin system. Several of its degradation products including Ang III (obtained by deletion of the N terminal amino acids), Ang IV (obtained by deletion of the two N terminal amino acids), and Ang II (1-7) (obtained by deletion of the C terminal amino acid), also possess biological functions. These peptides are formed via the activity of several enzymes: angiotensin--converting enzyme, aminopeptidases A and N, neutral endopeptidase and prolylendopeptidase. Ang III possesses most of the properties of Ang II and shares the same receptors AT1 and AT2. In addition this peptide is particularly important in brain physiology and plays a major role in the secretion of arginine vasopressine. Ang IV possesses its own receptors distinct from AT1 and AT2. Some of its effects (for example, stimulation of the synthesis of the type 1 inhibitor of plasminogen activator by endothelial cells) were previously attributed to Ang II. Others effects, like renal and cerebral vasodilatation, are opposed to Ang II effects. The role of Ang IV in renal physiology remains to be determined. Ang II (1-7) exhibits direct and indirect effects, the latter resulting from Ang II (1-7)-dependent formation of nitric oxide and vasodilatory prostaglandins. Ang II (1-7) potentiates the hypotensive effect of bradykinin and plays also a major role in the control of the hydroelectrolytic balance. It possesses its own receptor: AT1-7, recognizable by (sar1-thr8) Ang II or Sarthran. Finally Ang II (1-7) is converted into Ango II (1-5), by angiotensin-converting enzyme. This peptide is inactive. All of these enzymes, peptides and receptors are present in kidney. Thus the renin-angiotensin system appears to be much more complicated than thought a few years ago, setting the problem of new therapeutic tools for the treatment of hypertension and glomerulosclerosis.
Chansel
D
D
INSERM 4889, Hôpital Tenon, Paris.
Ardaillou
R
R
D000804:Angiotensin II / Q000031:analogs & derivatives / Q000378:metabolism*; D000805:Angiotensin III / Q000378:metabolism; D000818:Animals; D010450:Endopeptidases / Q000378:metabolism; D006801:Humans; D010446:Peptide Fragments / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism
D010446:Peptide Fragments; D000804:Angiotensin II; D000805:Angiotensin III; C012877:angiotensin II, des-Asp(1)-des-Arg(2)-Ile(5)-; D010450:Endopeptidases; D007703:Peptidyl-Dipeptidase A
Les métabolites actifs dérivés de l'angiotensine II.