Specific measurement of angiotensin metabolites and in vitro generated angiotensin II in plasma

Details

Serval ID
serval:BIB_EF444F3ED0E3
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Specific measurement of angiotensin metabolites and in vitro generated angiotensin II in plasma
Journal
Hypertension
Author(s)
Nussberger  J., Brunner  D. B., Waeber  B., Brunner  H. R.
ISSN
0194-911X (Print)
Publication state
Published
Issued date
06/1986
Volume
8
Number
6
Pages
476-82
Notes
In Vitro
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jun
Abstract
Combining high-performance liquid chromatography with radioimmunoassay enabled the precise measurement of different angiotensins and their metabolites in plasma. Peptides were extracted from 2 ml of plasma by reversible adsorption to phenylsilyl-silica, separated by isocratic high-performance liquid chromatography, and quantitated by radioimmunoassay using a sensitive but suitably cross-reacting angiotensin II antiserum. For the C-terminal angiotensin II metabolites (2-8)heptapeptide, (3-8)hexapeptide, and (4-8)pentapeptide, overall recoveries of 10 fmol peptide added to 1 ml of plasma were (mean +/- SD), 74 +/- 6, 68 +/- 8, and 67 +/- 11%, respectively. The detection limit for these peptides in plasma was 0.2 fmol/ml. Blanks were below the detection limits. In eight seated normal subjects treated for 4 days with enalapril, 20 mg p.o., q.d., angiotensin II metabolites tended to decrease during the 4 postdrug hours. However, their cumulated concentration in relation to octapeptide increased from 54 to 163% on Day 1 and from 62 to 103% on Day 4. After 4 hours of converting enzyme inhibition with enalapril there was still a close correlation between plasma renin activity and angiotensin-(1-8)octapeptide level (r = 0.83, p less than 0.05) and between blood angiotensin I and angiotensin-(1-8)octapeptide levels (r = 0.86, p less than 0.01). Adding angiotensin I in vitro raised the angiotensin-(1-8)octapeptide levels after incubation at 4 degrees C for 4 hours. Thus, immunoreactive "angiotensin II" does not disappear after converting enzyme inhibition largely because of the cumulated contribution of cross-reacting metabolites and partly because of in vitro generation of true angiotensin II.
Keywords
Adult Angiotensin I/blood Angiotensin II/*blood Angiotensin III/blood Angiotensin-Converting Enzyme Inhibitors Angiotensins/*blood/immunology Chromatography, High Pressure Liquid Cross Reactions Enalapril/pharmacology Humans Male Radioimmunoassay
Pubmed
Web of science
Create date
05/03/2008 16:41
Last modification date
20/08/2019 16:17
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