@article{3038366876774a05bbb6aecf9322c887,
title = "lα,25-dihydroxyvitamin D3 receptor: competitive binding of vitamin D analogs",
abstract = "The intestinal nuclear receptor for lα,25-dihydroxyvitamin D3 has been utilized to determine the ability of vitamin D-active sterols to compete with this hormone at the molecular level. 25-Hydroxyvitamin D3 and lα-hydroxyvitamin D3 must be present in 150 and 450 times the concentration respectively of lα,25-dihydroxyvitamin D3, in vitro, to displace the physiologic hormone. These data indicate that: i) superphysiologic levels of 25-hydroxyvitamin D3 may simulate lα,25-dihydroxyvitamin D3 and act directly on isolated target organs and ii) the biologic potency observed for low doses of lα-hydroxyvitamin D3, in vivo, is probably the result of 25-hidroxylation of the lα-derivative to form lα,25-dihydroxyvitamin D3.",
author = "Brumbaugh, \{Peter F.\} and Haussler, \{Mark R.\}",
note = "Funding Information: an efficient (but not naturally occurring) precursor of 1(x,25-(OH)2-D3 rather than en ideal analog of the hormone . We propose that this analog is rapidly 25-hydro\textasciitilde{}lated and acts by metabolic transformation to 1a,25-(OH)2-D3. The phenomenon of 25-hydroxylation, in yivo, probably also is applicable to dihydrotachyaterol2, which does not bind effectively to the hormone receptor (Fig . 2), but is biologically active at high dose levels . In addition to providing possible explanations of the previous data on the biological activity of vitamin D and its analogs, extension of these studies may be of value in designing analogs of the vitamin to correct renal oateodyetropby, vitamin D-resistant rickets, and possibly osteoporo-sis. Flarthexmore, the specificity and high affinity of this receptor for 1,25-(OH)2-D3 suggest that it could be utilized in the development of a competitive protein binding assay for the hormone . Ackno\textasciitilde{}le da\textasciitilde{}ents - This research was supported in part by USPHS Grant AM15781, USPHS Training Grant GM01982 funds from the Arizona Heart Association. Rote Added In Proof - Recently and Norman reported that a 250 fold excess of 25-OH-D3 50\textasciitilde{} reduction of \textasciitilde{}3iL\textasciitilde{}11Y,25-(OH)2-D3 bind- ing to thin receptor",
year = "1973",
month = dec,
day = "16",
doi = "10.1016/0024-3205(73)90120-3",
language = "English (US)",
volume = "13",
pages = "1737--1746",
journal = "Life Sciences",
issn = "0024-3205",
publisher = "Elsevier Inc.",
number = "12",
}