ISSN:
1435-5604
Keywords:
Key words: 1
;
25(OH)2D3
;
1
;
25(OH)2D3-lactone
;
osteoclast-like cell
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract: We have used a human bone marrow culture system that forms multinucleated cells (MNCs), 50% of which express the osteoclast phenotype, to examine the 23(S)25(R)-1,25-dihydroxyvitamin D3-26,23-lactone (1,25-D3-lactone) on osteoclast-like cell formation. The 1,25-D3-lactone is a vitamin D3 metabolite that has recently been detected in human serum under physiological conditions at concentrations of approximately 131 pg/ml (3 × 10−10 M) and can inhibit bone resorption induced by 1,25-dihydroxyvitamin D3 (1,25-D3) in vivo and in vitro. We examined the effects of the 1,25-D3-lactone on the formation of MNC that cross-reacted with 23C6 monoclonal antibody (23C6-positive MNC), which preferentially binds to osteoclasts. All metabolites of 1,25-D3 except the 1,25-D3-lactone increased both total and 23C6-positive MNC formation in a dose-dependent manner. In contrast, the 1,25-D3-lactone inhibited both total and 23C6-positive MNC formation, whether the cultures were treated with 1,25-D3, parathyroid hormone, or interleukin-1β, all potent stimulators of MNC formation. This inhibitory action of 1,25-D3-lactone on MNC formation was very similar to the inhibitory effects of calcitonin. These data suggest that (1) 1,25-D3-lactone is a potent natural inhibitor of formation of cells with the osteoclast phenotype at physiological concentrations and (2) the inhibition of these cells by 1,25-D3-lactone may not result solely from its competitive binding to the 1,25-D3 receptor.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s007740050021
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