Involvement of different ion channels in osteoblasts' and osteocytes' early responses to mechanical strain

doi:10.1016/S8756-3282(96)00260-8

Bone

Volume 19, Issue 6, December 1996, Pages 609-614

https://doi.org/10.1016/S8756-3282(96)00260-8 Get rights and content

Abstract

The involvement of functional ion channels in previously documented early responses of osteocytes and osteoblasts to mechanical strain in bone tissue was investigated in explants of rat ulnae by the use of ion channel blockers. Gadolinium chloride (a blocker of stretch/shear-sensitive cation channels) elevated basal prostaglandin (PG) E₂ and prostacyclin (PGI₂) release and osteocyte glucose-6-phosphate dehydrogenase (G6PD) activity, but was associated with a reduction in basal nitric oxide (NO) production. Gadolinium abolished loading-related increases in the release of PGI₂ and NO and osteocyte G6PD activity. Gadolinium also reduced the loading-related release of PGE₂ assumed to originate from osteoblasts and the magnitude of loading-related increases in G6PD activity in these cells. Nifedipine (a blocker of L-type voltage-dependent calcium channels) had no effect on basal levels of prostanoid or NO release, or G6PD activity in osteocytes or osteoblasts, and did not affect loading-related release of PGI₂ or increase in osteocyte G6PD. However, nifedipine prevented loading-related increases in PGE₂ and NO release and osteoblast G6PD activity. These results are consistent with osteocytes' response to bone loading requiring activatable ion channels sensitive to gadolinium, but not those sensitive to nifedipine. In osteoblasts, the early responses to bone loading appear to be associated with ion channels sensitive to gadolinium and nifedipine; however, the nifedipine-sensitive channels seem to have the dominant effect.

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Original articleInvolvement of different ion channels in osteoblasts' and osteocytes' early responses to mechanical strain

Abstract

Bone

Bone Miner

Cell

Biochem Biophys Acta

Bone

J Biol Chem

Gadolinium blocks low- and high-threshold calcium currents in pituitary cells

Am J Physiol

Practical histochemistry

Estrogen enhances the stimulation of bone collagen synthesis by loading and exogenous prostacyclin, but not prostaglandin E2, in organ cultures of rat ulnae

J Bone Miner Res

Indomethacin has distinct early and late actions on bone formation induced by mechanical stimulation

Am J Physiol

Early strain-related changes in cultured embryonic chick tibiotarsi parallel those associated with adaptive modeling in vivo

J Bone Miner Res

Multiple forms of mechanosensitive ion channels in osteoblast-like cells

Pflugers Arch

Stretch-activated single-channel and whole cell currents in vascular smooth muscle cells

Am J Physiol

Cellular responses to mechanical loading in vitro

J Bone Miner Res

Drug- and disease induced regulation of voltage-dependent calcium channels

Pharm Rev

Nitric oxide is an early mediator of the induction of bone formation by mechanical strain

J Bone Miner Res

Vasoconstriction and increased flow: Two principal mechanisms of shear stress-dependent endothelial autocoid release

Am J Physiol

The role of bone cells in increasing metaphyseal hard tissue in rapidly growing rats treated with prostaglandin E2

Bone

Sensitivity of osteocytes to biomechanical stress in vitro

FASEB J

Selective inhibition of agonist-induced but not shear stress dependent release of endothelial autocoids by thapsigargin

Br J Pharmacol

The effect of mechanical load and oestrogen on the development of long bone architecture

PhD thesis

The effect of strain on bone cell prostaglandin E2 release: A new experimental method

Calcif Tissue Int

Original article
Involvement of different ion channels in osteoblasts' and osteocytes' early responses to mechanical strain

Estrogen enhances the stimulation of bone collagen synthesis by loading and exogenous prostacyclin, but not prostaglandin E₂, in organ cultures of rat ulnae

The role of bone cells in increasing metaphyseal hard tissue in rapidly growing rats treated with prostaglandin E₂

The effect of strain on bone cell prostaglandin E₂ release: A new experimental method