title: Radioreceptor assay for 1 alpha,25-dihydroxyvitamin D3.
abstract: A competitive protein binding assay with a sensitivity of 80 picograms has been developed for 1alpha,25-dihydroxyvitamin D(3), the hormonal form of vitamin D(3). lalpha,25-Dihydroxyvitamin D(3) displaced tritiated hormone from a cytosol-chromatin receptor preparation isolated from chick small intestine, providing a simple assay for the hormone. The concentration of lalpha, 25-dihydroxyvitamin D(3) in human plasma, as determined by this assay, is approximately 6 nanograms per 100 milliliters; in patients with renal disease the concentration of this kidney-produced hormone is significantly lower.
mesh_terms: D000818:Animals; D002118:Calcium / Q000097:blood; D002645:Chickens; D002843:Chromatin / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004100:Dihydroxycholecalciferols / Q000097:blood; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood*; D006961:Hyperparathyroidism / Q000097:blood; D007011:Hypoparathyroidism / Q000097:blood; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000097:blood; D008722:Methods; D011869:Radioligand Assay; D011955:Receptors, Drug; D012279:Rickets / Q000097:blood; D014316:Tritium
chemical_list: D002843:Chromatin; D004100:Dihydroxycholecalciferols; D006887:Hydroxycholecalciferols; D011955:Receptors, Drug; D014316:Tritium; D002118:Calcium