Specific radioimmunoassay for ovine bone gla-protein (osteocalcin).
We developed a sensitive and specific radioimmunoassay for ovine bone gla-protein (osteocalcin) using a polyclonal rabbit antibody raised against ovine bone gla-protein. Bone from lambs was extracted in 0.5 mol/l EDTA and desalted on Sephadex G-25. Bone gla-protein was purified by gel filtration chromatography over Sephadex G-100 and ion-exchange chromatography on DEAE-Sephadex A-25. The protein, subjected to monodimensional electrophoresis migrated as a single spot in SDS PAGE with the same apparent molecular weight of 12 kD as bovine bone gla-protein. The amino acid composition of purified bone gla-protein was in agreement with a previous publication. The competitive RIA uses 125I-labelled bone gla-protein as a tracer and a complex of a second antibody and polyethylene glycol to separate free and antibody-bound 125I-labelled bone gla-protein. The intra- and inter-assay variations are less than 6 and 10%, respectively. There is no reactivity of our antisera with dog sera. The cross-reactivity is only partial with calf and human sera and complete with ovine sera. We measured bone gla-protein levels in serum of 96 normal male sheep of different ages. Serum bone gla-protein rapidly and significantly (P less than 0.001) decreased from 535 +/- 169 microgram/l at birth, to 240 +/- 43 microgram/l at 45 days, 152 +/- 44 micrograms/l at 90 days, and 5.9 +/- 0.7 microgram/l at 7 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)
Pastoureau
P
P
Unité INSERM 234, Hôpital E. Herriot, Lyon, France.
Merle
B
B
Delmas
P D
PD
D000367:Age Factors; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001842:Bone and Bones / Q000032:analysis; D002135:Calcium-Binding Proteins / Q000032:analysis*; D015675:Osteocalcin; D011863:Radioimmunoassay / Q000379:methods*; D012756:Sheep
D000596:Amino Acids; D002135:Calcium-Binding Proteins; D015675:Osteocalcin