Assays to measure nanomolar levels of the renin inhibitor CGP 38 560 in plasma

Journal Article · Sun Oct 01 00:00:00 EDT 1989 · Hypertension (Dallas); (USA)

DOI:https://doi.org/10.1161/01.HYP.14.4.379· OSTI ID:5265055

Cumin, F; de Gasparo, M; Wood, J M; Schnell, C; Frueh, F; Graf, P ^[1]

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1. Ciba-Geigy Limited, Basel (Switzerland)

A radioinhibitor binding assay and an enzyme inhibition assay have been developed to measure plasma levels of CGP 38 560, a potent human renin inhibitor. The detection limit of the assays was between 0.5 and 1 pmol/ml. There was a good correlation (r = 0.989) between the two assays for the measurement of human plasma spiked with CGP 38 560 in concentrations from 1.9 nM to 12 microM. Intra-assay variability was 6.1-17.3% and 4.4-27.2% for the radioinhibitor binding assay and the enzyme inhibition assay, respectively. Interassay variability was 6.0-28.2% and 3.8-28.4% for the radioinhibitor binding assay and the enzyme inhibition assay, respectively. Blood samples were collected during a pharmacological study performed in normotensive human volunteers on an unrestricted diet who were infused during a 30-minute period with CGP 38 560 A (50 micrograms/kg). Similar values for the concentrations of renin inhibitor in plasma were obtained with the radioinhibitor binding assay and the enzyme inhibitor assay, and there was a significant correlation between values obtained with the two different methodologies (r = 0.94). The plasma levels of renin inhibitor reached a maximum at the end of infusion and then decreased rapidly, indicating a short plasma half-life. The changes in biochemical parameters, plasma renin activity, and plasma concentration of active renin could be related to the concentrations of CGP 38 560 measured in the plasma.

• OSTI ID: 5265055
• Journal Information: Hypertension (Dallas); (USA), Vol. 14:4; ISSN 0194-911X
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ENZYME INHIBITORS
MEASURING METHODS
ANGIOTENSIN
BIOLOGICAL HALF-LIFE
BLOOD PLASMA
BLOOD PRESSURE
CPB
HEART
IN VITRO
MAN
RADIOASSAY
RADIOENZYMATIC ASSAY
RENIN
TRACER TECHNIQUES
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BODY
BODY FLUIDS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
DRUGS
ENZYMES
GLOBULINS
HYDROLASES
ISOTOPE APPLICATIONS
MAMMALS
MATERIALS
NONSPECIFIC PEPTIDASES
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HYDROLASES
PRIMATES
PROTEINS
VASOCONSTRICTORS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques