Hormonal regulation of [Ca(2+)](i) in periosteal-derived osteoblasts: effects of parathyroid hormone, 1,25(OH)(2)D(3) and prostaglandin E(2)

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Authors

Colleges, School and Institutes

Abstract

The effects of hormonal modulators of osteoblast function, parathyroid hormone, 1,25(OH)(2)D(3) and prostaglandins on [Ca(2+)](i) in periosteal-derived osteoblasts from rat femurs have been investigated. Our results show that application of parathyroid hormone PTH (10(-5) M) and prostaglandin E(2) (PGE(2)) (4 microM) result in a rapid heterogeneous elevation in [Ca(2+)](i) that, in the case of PTH, is dependent on both extracellular and intracellular sources of calcium. Variable responses to treatments have been found within populations of cells. The PGE(2) response is dose dependent. Treatment with 1,25(OH)(2)D(3) (10(-8) M) induces a brief (60-90 sec) elevation in [Ca(2+)](i) that is almost totally abolished in EGTA-buffered Ca(2+)-free medium. Interactive effects of multiple hormone treatments have been observed. Pretreatment with 1,25(OH)(2)D(3) results in near-total inhibition of the PTH and PGE(2) responses. In conclusion, modulation of [Ca(2+)](i) appears to play a role not only in the direct effects of osteotropic hormones on osteoblasts but also in the synergistic and antagonistic effects between circulating hormones.

Bibliographic note

Copyright 2000 Wiley-Liss, Inc.

Details

Original languageEnglish
Pages (from-to)163-71
Number of pages9
JournalJournal of Cellular Physiology
Volume183
Issue number2
Publication statusPublished - May 2000

Keywords

  • Animals, Second Messenger Systems, Calcium, Bone Resorption, Xanthenes, Aniline Compounds, Fluorescent Dyes, Parathyroid Hormone, Calcitriol, Rats, Osteoblasts, Dinoprostone, Intracellular Fluid, Periosteum, Cells, Cultured