In vitro renin inhibition to prevent generation of angiotensins during determination of angiotensin I and II.
To prevent in vitro generation of angiotensins, the renin inhibitor CGP 29287 (CGP) was added to blood sampling tubes. Plasma immunoreactive angiotensin (ir-ANG) I and II were simultaneously measured by radioimmunoassay after rapid and quantitative extraction from a single plasma sample on phenylsilylsilica (Bondelut PH). True plasma ANG-(1-8)octapeptide was determined after additional separation of the different angiotensins by high performance liquid chromatography. Ir-ANG II/CGP showed the known linear relationship with ANG-(1-8)octapeptide (r = 0.87, n = 23), but - in contrast to studies without addition of CGP - the y-axis intercept which presumably represents cross-reacting angiotensins other than ANG II was very small. Ir-ANG II/CGP concentrations fell below 1 fmol/ml after converting enzyme inhibition. The results suggest that CGP 29287 prevents in vitro generation of ANG I and ANG II as well as the ANG-metabolites. Ir-ANG I/CGP measured after Bondelut PH extraction of the plasma was strongly correlated with ir-ANG I obtained after blood ethanol extraction (r = 0.97, n = 23). Thus, it is now possible to measure reliably both ANG I and ANG II within the same plasma extract after a simple extraction procedure.
Nussberger
J
J
Division of Hypertension, University Hospital, Lausanne, Switzerland.
Brunner
D B
DB
Waeber
B
B
Brunner
H R
HR
D000803:Angiotensin I / Q000097:blood*; D000804:Angiotensin II / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D004656:Enalapril; D006801:Humans; D009842:Oligopeptides; D011863:Radioimmunoassay; D012083:Renin / Q000097:blood / Q000494:pharmacology; D000092502:Renin Inhibitors
D000803:Angiotensin I; D000804:Angiotensin II; D004656:Enalapril; D009842:Oligopeptides; D012083:Renin; D000092502:Renin Inhibitors; C045501:CGP 29287