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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1984-5-23
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pubmed:abstractText |
The biological activities of several 24-oxo and 26,23-lactone metabolites of vitamin D were determined in bone organ cultures. The 24-oxo metabolites were significantly more potent bone-resorbing agents than the lactones. 1,25-(OH)2-24-oxo-D3 had 0.18 X the bone-resorbing activity of 1,25-(OH)2D3 in fetal rat limb bones and was equipotent with 1,25-(OH)2D3 in neonatal mouse calvaria. In the limb bone system, 1,23,25-(OH)3-24-oxo-D3 had 0.08 X the activity of 1,25-(OH)2D3. 1,25-(OH)2D3 and 1,25-(OH)2-24-oxo-D3 had a similar time course of bone-resorbing effects in both bone culture systems. The most potent of the lactones, 1,25S-(OH)2D3-26,23R-lactone, had approximately 0.009 X the activity of 1,25-(OH)2D3 and approximately 500 times the activity of the 25S-OH-D3-26,23R-lactone. The 25S and 1,25S lactones were more potent than the 25R and 1,25R isomers. In experiments designed to determine whether either 1,25-(OH)2-24-oxo-D3 or 25R-OH-D3-26,23S-lactone could prevent the bone-resorbing activity of 1,25-(OH)2D3, no inhibitory effects were observed. The results suggest that conversion to the lactones represents a substantial inactivation step, whereas conversion to 24-oxo-derivatives results in less reduction in biological activity.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
May
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pubmed:issn |
0003-9861
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
230
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
424-9
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:6546849-Animals,
pubmed-meshheading:6546849-Bone Resorption,
pubmed-meshheading:6546849-Calcitriol,
pubmed-meshheading:6546849-Cells, Cultured,
pubmed-meshheading:6546849-Hydroxylation,
pubmed-meshheading:6546849-Lactones,
pubmed-meshheading:6546849-Mice,
pubmed-meshheading:6546849-Rats
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pubmed:year |
1984
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pubmed:articleTitle |
24-Oxo and 26,23-lactone metabolites of 1,25-dihydroxyvitamin D3 have direct bone-resorbing activity.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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