Problems connected with plasma renin activity measurements by angiotensin I radioimmunoassay
Details
Serval ID
serval:BIB_AAE7B946B048
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Problems connected with plasma renin activity measurements by angiotensin I radioimmunoassay
Journal
Hormone and Metabolic Research
ISSN
0018-5043 (Print)
Publication state
Published
Issued date
07/1975
Volume
7
Number
4
Pages
342-7
Notes
Journal Article --- Old month value: Jul
Abstract
The main application of the radioimmunoassay for angiotensin I is the measurement of plasma renin activity (PRA). Methods published for the measurement of PRA differ in many details and make the comparison of results difficult. This paper deals with some of the problems. 1. The radioactive labelling of angiotensin I using chloramine-T requires the purification of the labelled peptide. A method applying both anion exchange chromatography and gel filtration is described. It resulted in tracer angiotensins of very reproducible characteristics. 2. For the measurement of PRA, the pH of the plasma has to be adjusted prior to the incubation. The adjustment to the physiologic pH of 7.4 is recommended. 0.1 volume of a concentrated buffer controlled the pH during a three hours incubation without diluting the plasma too much. 3. At pH 7.4, EDTA, dimercaprol, and 8-hydroxyquinoline were found to inhibit converting enzyme and angiotensinases better than EDTA and DFP and should therefore be used as inhibiting agents. 4. Nonspecific cross reaction of antisera are the cause of the blank values when angiotensin I is measured in unextracted plasma. The problem of subtraction of a blank may be minimized by the selection of an antiserum of high specificity which shows no or only little nonspecific cross reaction. Lor or unmeasurable blank values will result.
Keywords
Angiotensin II/*analysis/immunology
Antibody Specificity
Chromatography, Ion Exchange
Dimercaprol/pharmacology
Edetic Acid/pharmacology
Hydrogen-Ion Concentration
Hydroxyquinolines/pharmacology
Isotope Labeling
Protease Inhibitors
Radioimmunoassay/methods
Renin/*blood
Pubmed
Web of science
Create date
05/03/2008 17:39
Last modification date
20/08/2019 16:14