Direct, simplified, and sensitive assay of angiotensin II in plasma extracts performed with a high-affinity monoclonal antibody.
A very simple, fast, and sensitive RIA of angiotensin (Ang) II has been developed, based on a monoclonal antibody with high affinity and specificity, making possible the direct measurement of circulating Ang II in human plasma after solid-phase extraction. The purified monoclonal antibody 4D8 has an association constant of 1.3 x 10(11) L/mol with Ang II and a cross-reactivity of < 1% for Ang I. The assay can detect as little as 0.8 fmol of Ang II in 2 mL of plasma and is not influenced by the presence of Ang I. Analytical recoveries between 112% and 116% were obtained for Ang II added to human plasma at physiological concentrations. Comparison of the RIA with a reversed-phase, high-performance liquid chromatographic method followed by RIA to measure Ang II in human plasma samples from normal and hypertensive subjects--and from normotensive subjects before and after an acute inhibition of angiotensin-converting enzyme with captopril (50 mg)--showed a high degree of correlation (r2 = 0.93) between the two methods.
Simon
D
D
Sanofi Recherche, Montepellier, France.
Romestand
B
B
Huang
H
H
Badouaille
G
G
Fehrentz
J A
JA
Pau
B
B
Marchand
J
J
Corvol
P
P
D000804:Angiotensin II / Q000097:blood* / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000915:Antibody Affinity; D000918:Antibody Specificity; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006973:Hypertension / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D010446:Peptide Fragments / Q000276:immunology; D011863:Radioimmunoassay / Q000379:methods*; D012016:Reference Values
D000911:Antibodies, Monoclonal; D010446:Peptide Fragments; D000804:Angiotensin II