Presence of angiotensin peptides in human urine

Immunoreactive angiotensin I and angiotensin II were found in human urine that was purified on octadecasilylsilica cartridges. The daily excretion of angiotensin I and II in healthy volunteers was 189.00 (SE 38.36) and 17.54 (SE 3.07) pmol/24 h or 148.09 (SE 32.22) and 12.82 (SE 2.34) pmol/L, respectively (n = 12). No circadian rhythm was observed in the excretion patterns of angiotensin I and II. In vitro degradation of angiotensin I or II could not be detected in acidified urine samples. A marked increase in the excretion of angiotensin I and II could be demonstrated in patients with anaphylactoid reactions to drugs and food additives after oral challenge. Immunoreactive angiotensin I and II could be characterized by HPLC as Ile5-angiotensin I, Ile5-angiotensin II, and angiotensin II metabolites.