Inhibitory effect of amylin on basal and parathyroid hormone-stimulated bone resorption in cultured neonatal mouse calvaria
Pietschmann, P.; Farsoudi, K.H.; Hoffmann, O.; Klaushofer, K.; Hörandner, H.; Peterlik, M.
Bone 14(2): 167-172
1993
ISSN/ISBN: 8756-3282 PMID: 8334035 Document Number: 413901
Amylin is a secretory product of pancreatic beta-cells which shares major sequence homology with calcitonin gene-related peptide. In neonatal mouse calvaria maintained in organ culture for 72 h, amylin inhibited basal (i.e., unstimulated) resportion in medium concentrations above 2.5 times 10-9 M. In addition, amylin ( gtoreq 1.0 times 10-7 M) in a calcitonin-like fashion transiently inhibited bone resorption induced by 1.0 times 10-8 M PTH ("escape phenomenon"). Pretreatment of calvarial bones with amylin (1.0 times 10-8 -1.0 times 10-6 M) for 72 h attenuated the subsequent response to 1.0 times 10-8 M PTH. Changes in location and appearance of osteoclasts in amylin-treated bones, as visualized by light microscopy, suggest that amylin inhibits bone resorption by causing a loss of specialized contact zones to the mineralized matrix in resorbing osteoclasts, and in addition, by preventing retraction of osteoblasts from the mineralized surface which impedes attachment of osteoclasts thereon.