ISSN:
1432-0827
Keywords:
Lead
;
Prostaglandin E2
;
Osteoclast-like cell formation
;
Mouse bone marrow cells
;
Cyclic adenosine 3′,5′-monophosphate
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
,
Physics
Notes:
Abstract To examine an effect of lead (Pb) on the process of osteoclast-like cell formation from its progenitors, we used a mouse bone marrow culture system in which osteoclast-like multinucleated cells (MNCs) were formed in response to bone-resorbing agents. In a 9-day culture period, Pb dose-dependently stimulated MNC formation over the concentration range 2–10 μM, whereas at 40 μM Pb, MNC formation declined. In an 11-day culture period, MNC formation reached a maximum at 5 μM Pb and decreased with increasing concentration of Pb at 10–40 μM. Pb-stimulated MNC formation was inhibited by both indomethacin and SC19220, an antagonist of prostaglandin E2 (PGE2) receptor. Pb stimulated the production of PGE2 in marrow cell cultures, suggesting that Pb-stimulated MNC formation is dependent on the production of PGE2. 3-Isobutyl-1-methylxanthine potentiated Pb-stimulated MNC formation and 2′,5′-dideoxyadenosine, an inhibitor of adenylate cyclase, inhibited it. A calcium ionophore A23187 increased Pb-induced MNC formation and verapamil, a calcium channel blocker, depressed it. It is possible that a PGE2-induced increase in the levels of cyclic adenosine 3′,5′-monophosphate (cAMP) and calcium ions in marrow cells is involved in Pb-induced MNC formation. Pb and parathyroid hormone showed a synergistic stimulation on MNC formation. From these results, Pb is thought to induce osteoclast-like cell formation by a mechanism involving PGE2 which increases the intracellular levels of cAMP and calcium ions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00296069
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