title: The number of tartrate-resistant acid phosphatase-positive osteoclasts on neonatal mouse parietal bones is decreased when prostaglandin synthesis is inhibited and increased in response to prostaglandin E2, parathyroid hormone, and 1,25 dihydroxyvitamin D3.
abstract: The culture of parietal bones from 4-day old mice in indomethacin (Ind) for 1 day caused a large reduction in the number of tartrate-resistant acid phosphatase positive osteoclasts (TRAP + OC) relative to both control bones and to freshly isolated bones. This reduction did not occur if prostaglandin E2 (PGE2) was present. When 5-bromo-2'-deoxyuridine (BDU) was injected into 4-day old mice, newly formed TRAP + OC nuclei became labeled 1 day later; these bones were then cultured with Ind for 1 day. TRAP + OC and newly labeled TRAP+OC nuclei were commensurately decreased in number. This suggests an active down-regulation rather than merely the inhibition of new TRAP+OC formation. Incubation of bones with Ind and either PGE2, parathyroid hormone, or 1,25 dihydroxyvitamin D3 for 6 hours following a 1-day preincubation in Ind, resulted in an increase in TRAP + OC compared with Ind alone. Using BDU labeling in vitro and in vivo, we show that this increase in number of TRAP+OC is not the result of cell proliferation, but rather differentiation of postmitotic precursors.
authors.affiliation: Charles Salt Research Centre, Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire, United Kingdom.
authors.forename: M J
authors.initials: MJ
authors.lastname: Marshall
authors.forename: I
authors.initials: I
authors.lastname: Holt
authors.forename: M W
authors.initials: MW
authors.lastname: Davie
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001973:Bromodeoxyuridine / Q000737:chemistry / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D003470:Culture Media; D015232:Dinoprostone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects; D051379:Mice; D008808:Mice, Inbred CBA; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010294:Parietal Bone / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011453:Prostaglandins / Q000096:biosynthesis; D013194:Staining and Labeling
chemical_list: D003470:Culture Media; D010281:Parathyroid Hormone; D011453:Prostaglandins; D000135:Acid Phosphatase; D002117:Calcitriol; D001973:Bromodeoxyuridine; D015232:Dinoprostone