Development of a sensitive and specific assay system for cholecystokinin tetrapeptide.
Peptides
; 18(6): 869-75, 1997.
Article
en En
| MEDLINE
| ID: mdl-9285937
ABSTRACT
Cholecystokinin is a gastrointestinal and neuropeptide which has been implicated in a wide range of physiological and behavioral processes. We have developed a sensitive and specific assay system to measure the various forms of cholecystokinin (CCK) in human plasma. This 3-step system involves i) extraction of CCK fragments from plasma using reverse phase chromatography; ii) separation of peptides by high performance liquid chromatography; and iii) detection and quantification of peptides with a double-antibody radioimmunoassay, using an antibody raised against cholecystokinin tetrapeptide (CCK-4) coupled to thyroglobulin and 125I Bolton-Hunter CCK-4 as tracer. The antibody detects CCK-4, sulfated CCK-8 (CCK-8S) and nonsulfated CCK-8 (CCK-8ns) with equal affinity. The lower limit of detection is 2.7 fmol, with an ED50 of 10.6 +/- 2.2 fmol. Mean CCK-like immunoreactivity (CCK-LI) in the plasma of 12 healthy subjects was determined to be 12.9 +/- 2.1 pM CCK-4 equivalents. Concentrations of each individual peptide in plasma were determined to be 1.0 +/- 0.2 pM, 3.4 +/- 0.8 pM and 1.9 +/- 0.4 pM for CCK-4, CCK-8s and CCK-8ns respectively.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Tetragastrina
Tipo de estudio:
Diagnostic_studies
Límite:
Adult
/
Animals
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Peptides
Año:
1997
Tipo del documento:
Article
País de afiliación:
Canadá