Studies on the mode of action of calciferol. XIII. Development of a radioimmunoassay for vitamin D-dependent chick intestinal calcium-binding protein and tissue distribution

Journal Article · Tue May 01 00:00:00 EDT 1979 · Endocrinology; (United States)

OSTI ID:5437639

Christakos, S; Friedlander, E J; Frandsen, B R; Norman, A W

A RIA for chick intestinal calcium-binding protein (CaBP) has been developed with a sensitivity of 1 ng. The antiserum was generated in rabbits injected with highly purified vitamin D-dependent chick intestinal CaBP. The assay employs the double antibody technique, and /sup 125/I-labeled CaBP was prepared using chloramine T. Low molecular weight peptide hormones and normal rabbit, rat, and human serum proteins show no cross-reactivity in the assay. Measurements of chick intestinal and kidney CaBP by RIA showed a good correlation with measurements of CaBP by the radial immunodiffusion method. The assay is reproducible (interassay variability, 16.3%) and precise (intraassay variability, 4.0%). The concentration of immunoreactive CaBP (iCaBP) in chick serum (2.7 ng/ml serum) can now be measured as early as 8 h after the administration of 6.5 nmol 1,25-dihydroxyvitamin D/sub 3/; a maximum of 11 ng/ml is reached at 20 h. The level of CaBP in chick serum was found to be dependent on the dose of vitamin D/sub 3/ or 1,25-dihydroxyvitamin D/sub 3/ administered to the animal.

• Research Organization: Univ. of California, Riverside
• OSTI ID: 5437639
• Journal Information: Endocrinology; (United States), Vol. 104:5
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CHICKENS
INTESTINES
PROTEINS
RADIOIMMUNOASSAY
CHOLECALCIFEROL
EXPERIMENTAL DATA
IODINE 125
ISOLATED VALUES
ANIMALS
BETA DECAY RADIOISOTOPES
BIRDS
BODY
DATA
DATA FORMS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
FOWL
GASTROINTESTINAL TRACT
INFORMATION
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
RADIOASSAY
RADIOISOTOPES
TRACER TECHNIQUES
VERTEBRATES
VITAMIN D
VITAMINS
550201* - Biochemistry- Tracer Techniques