Estimation of Angiotensin II Concentration in Human Plasma by Radioimmunoassay. Some Applications to Physiological and Clinical States

Abstract

Abstract. A radioimmunoassay method for the measurement of angiotensin II in human plasma is described. The hormone is extracted quickly by Dowex (H+) particles. Angiotensinase and converting enzyme are inhibited by a mixture of EDTA and o‐phenanthroline. Blood samples can be processed at room temperature. Recoveries from blood were 83%± 11 (SD), n=44. Replicates within one assay varied about their mean with a standard deviation of ± 10%, n=16. The smallest concentration detectable, using 10 ml plasma samples, was 2 pg/ml plasma. Peripheral venous plasma concentrations in 33 normal adults ranged from 5 to 35 pg/ml. Plasma angiotensin II concentrations in some physiological and clinical conditions are reported.

Enalapril maleate and a lysine analogue (MK‐521) in normal volunteers; relationship between plasma drug levels and the renin angiotensin system.

“…Plasma angiotensin II concentrations were quantitated using a modification of the method described by Dusterdieck & McElvee (1971) and plasma converting enzyme activity by a radioenzymatic assay. The characteristics of these methods in our laboratory have been described previously .…”

Stimulation of renin secretion by potassium-channel activation with cromakalim

“…Mean arterial BP was calculated as the sum of the diastolic and one-third of the pulse pressure. Plasma and urinary sodium and potassium were measured by flame photometry; calcium and creatinine by Greiner autoanalyser (Greiner SA, Langenthal, Switzerland); PRA, plasma ANGII, aldosterone and irANP by radioimmunoassay [12][13][14][15] and plasma catecholamines by high performance liquid chromatography with electrochemical detection (Waters, Milford, MA: [16]. The methods have been reported previously [17][18][19].…”

The effect of a 5‐HT antagonist, ketanserin, on blood pressure, the renin‐angiotensin system and sympathoadrenal function in normal man.

“…Plasma active renin concentration (Miller et al, 1980), angiotensin II (Dusterdieck & McElwee, 1971), cortisol and aldosterone (Nicholls et al, 1980) were measured by radioimmunoassay and sodium and potassium by atomic adsorption spectrophotometry. Plasma noradrenaline was measured by a modification (Ball et al, 1981) of the radioenzymatic method of Da Prada & Zurcher (1976); serum ketanserin using high pressure liquid chromatography (Davies, 1983).…”