Please use this identifier to cite or link to this item:
Scopus Web of ScienceĀ® Altmetric
Type: Journal article
Title: Effects of Continuous Calcitonin Treatment on Osteoclast-like Cell Development and Clacitonin Receptor Expression in Mouse Bone Marrow Cultures
Author: Ikegame, M.
Rakopoulos, M.
Martin, T.
Moseley, J.
Findlay, D.
Citation: Journal of Bone and Mineral Research, 1996; 11(4):456-465
Publisher: Excerpta Medica
Issue Date: 1996
ISSN: 0168-051X
Abstract: Continuous treatment with calcitonin (CT) to inhibit osteoclastic bone resorption results in acquired resistance. The mechanisms of this "escape" phenomenon are not yet established. The aim of this study was to examine the effects of continuous treatment with CT on the generation of osteoclasts and calcitonin receptor (CTR) expression in mouse bone marrow cultures. This was done by daily CT treatment of mouse bone marrow cultures from day 0, when only undifferentiated mononuclear precursors of osteoclast-like cells were present, or commencing from day 6, when differentiated osteoclast-like cells were abundant. The response to CT treatment was determined by quantitation of cells positive for tartrate-resistant acid phosphatase (TRAP) and binding of 125I-salmon CT. Calcitonin receptor and TRAP mRNA levels were determined using semi-quantitative reverse transcription/polymerase chain reaction. When cultures were treated with CT from day 0, TRAP-positive multinucleated cells appeared. These cells expressed only very low levels of CTR or CTR mRNA and were morphologically indistinguishable from osteoclast-like cells formed in control cultures. They also displayed the ability to resorb bone. Continuous CT treatment of cultures from day 6 rapidly reduced the CTR mRNA levels, with a t1/2 of 6 to 12 h, and these levels remained low thereafter. 125I-salmon CT binding capacity, as determined by autoradiography, was lost in parallel. These effects were specific for the CTR since there was no consistent effect on TRAP mRNA levels. Based on these data, we suggest that the "escape" phenomenon may result from a prolonged CT-induced loss of CT responsiveness due, at least in part, both to reduced synthesis of CTR, and to the appearance in bone of CTR-deficient osteoclasts.
Keywords: Humerus
Bone Marrow Cells
Cells, Cultured
Giant Cells
Bone Marrow
Mice, Inbred C57BL
Bone Resorption
Iodine Radioisotopes
Acid Phosphatase
Receptors, Calcitonin
RNA, Messenger
DNA Primers
Microscopy, Electron, Scanning
Polymerase Chain Reaction
Cell Differentiation
Binding Sites
Base Sequence
Molecular Sequence Data
Tartrate-Resistant Acid Phosphatase
DOI: 10.1002/jbmr.5650110406
Appears in Collections:Aurora harvest
Orthopaedics and Trauma publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.