title: Effects of cyclosporine A on chick osteoclasts in vitro.
abstract: We have studied the effects of cyclosporine A (CsA) on basal and bovine parathyroid hormone (1-34) (bPTH)-stimulated bone resorption by osteoclasts in 24-hour cultures of chick long bone cells. At a high concentration (10 micrograms/ml), CsA had a cytotoxic effect on both osteoclasts and mononuclear cells in the culture. At 1 microgram/ml, CsA inhibited basal and bPTH-stimulated bone resorption but was not cytotoxic over 24 hours. We also studied the binding of bPTH to the osteoblastic cell line, Saos-2, and chick long bone cells in suspension culture. CsA inhibited bPTH binding in Saos-2 in a dose-dependent manner; inhibition of binding was also observed in chick bone cells. The effects of CsA on osteoclast viability and resorptive function may be due to a direct effect on the osteoclasts and/or to an interaction with the nonosteoclastic cell population in the culture.
authors.affiliation: Regional Bone Center, Helen Hayes Hospital, New York State Dept. of Health, West Haverstraw 10993.
authors.forename: M H
authors.initials: MH
authors.lastname: Chowdhury
authors.forename: V
authors.initials: V
authors.lastname: Shen
authors.forename: D W
authors.initials: DW
authors.lastname: Dempster
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001862:Bone Resorption; D002452:Cell Count; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002645:Chickens; D016572:Cyclosporine / Q000494:pharmacology*; D010010:Osteoclasts / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D010281:Parathyroid Hormone / Q000378:metabolism / Q000494:pharmacology*; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D010281:Parathyroid Hormone; D010446:Peptide Fragments; C025076:parathyroid hormone (1-34), bovine; D016572:Cyclosporine