A simple enzyme-linked immunosorbent assay of human osteocalcin.
A heterologous ELISA for measurement of osteocalcin (bone Gla-protein) is described, involving biotinylated bovine osteocalcin and polyclonal antibodies. The log-linear range was 2.3-37.5 micrograms/L. Between-run (total) and within-run CVs (n = 10) were 5.7-6.4 and 5.9-6.1%, respectively; analytical recoveries ranged from 92% to 108%. Comparison of our method (x) with an RIA (y) yielded y = 1.10 x -0.01 microgram/L, Sylx = 1.4 micrograms/L, r = 0.958 (n = 167). Serum osteocalcin in healthy premenopausal women (n = 29) was 8.7 +/- 3.3 micrograms/L (mean +/- SD) and 11.8 +/- 4.5 micrograms/L in early-postmenopausal women (n = 24). The assay was evaluated in a double-blind placebo-controlled study of healthy early-postmenopausal women, treated for 12 months with either (a) estrogen valerate plus medroxyprogesterone acetate (n = 18), (b) 17 beta-estradiol and desogestrel (n = 22), or (c) placebo (n = 17). Serum osteocalcin decreased significantly (P < 0.001) with either therapy, but increased (P < 0.05) with placebo.
Osteometer A/S, Biochemical Division, Rødovre, Denmark.
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Rosenquist
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Bonde
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Fledelius
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Qvist
D001710:Biotin; D017135:Desogestrel / Q000627:therapeutic use; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000706:statistics & numerical data; D004958:Estradiol / Q000031:analogs & derivatives / Q000627:therapeutic use; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D017258:Medroxyprogesterone Acetate / Q000627:therapeutic use; D015675:Osteocalcin / Q000097:blood*; D017698:Postmenopause / Q000097:blood; D011863:Radioimmunoassay
D015675:Osteocalcin; D004958:Estradiol; D001710:Biotin; D017135:Desogestrel; D017258:Medroxyprogesterone Acetate