True versus immunoreactive angiotensin II in human plasma

Détails

ID Serval
serval:BIB_B5A83D52F011
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
True versus immunoreactive angiotensin II in human plasma
Périodique
Hypertension
Auteur(s)
Nussberger  J., Brunner  D. B., Waeber  B., Brunner  H. R.
ISSN
0194-911X (Print)
Statut éditorial
Publié
Date de publication
06/1985
Volume
7
Numéro
3 Pt 2
Pages
I1-7
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: May-Jun
Résumé
To measure specifically angiotensin-(1-8)octapeptide, peptides were extracted from 2 ml of plasma by reversible adsorption to bonded-phase silica. The angiotensin-(1-8)octapeptide was then isolated by isocratic reversed-phase high-performance liquid chromatography and quantified by radioimmunoassay. The extraction recovery of 125I-angiotensin II added to 2 ml of plasma was 99 +/- 2% (mean +/- SD). The overall recovery of 5, 10, and 20 fmol unlabeled angiotensin II added to 1 ml of plasma was 80 +/- 10%. The coefficient of variation for within-assay precision was 0.06 and for between-assay precision 0.13. The detection limit was 0.4 fmol/ml. Buffer and plasma blanks were below the detection limit. Normal subjects on a free diet in supine position averaged 4.2 +/- 1.7 fmol/ml angiotensin-(1-8)octapeptide. Furosemide (40 mg p.o.) and standing increased these values to 22 +/- 7.6 fmol/ml. In four volunteers, immunoreactive "angiotensin II" (more or less angiotensin-like material) was measured serially before and after converting-enzyme inhibition (Hoe 498) with conventional Dowex extraction. At peak inhibition, plasma immunoreactive "angiotensin II" levels decreased by only 44%. In contrast, angiotensin-(1-8)-octapeptide isolated by high-performance liquid chromatography completely disappeared. In hypertensive patients receiving long-term treatment with enalapril, plasma levels of angiotensin-(1-8)octapeptide fell from 2.7 +/- 0.9 to 0.9 +/- 0.3 fmol/ml (mean +/- SEM) 2 hours after the morning dose, whereas levels of immunoreactive "angiotensin II" were not significantly changed. We found that this sensitive method specifically measured angiotensin-(1-8)octapeptide and demonstrated that true angiotensin II virtually disappears during converting-enzyme inhibition.
Mots-clé
Adult Aged Angiotensin II/*blood/immunology Antigen-Antibody Reactions Bicyclo Compounds/pharmacology Chromatography, High Pressure Liquid Cross Reactions Dipeptides/therapeutic use Enalapril Female Humans Hypertension/drug therapy/*metabolism Male Middle Aged Oligopeptides/pharmacology Radioimmunoassay Ramipril Renin-Angiotensin System Teprotide
Pubmed
Web of science
Création de la notice
05/03/2008 17:41
Dernière modification de la notice
20/08/2019 16:24
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