Electrical potential difference across bone membrane

Trumbore, D. C.; Heideger, W. J.; Beach, Kirk W.

doi:10.1007/bf02408535

Cited by 24 publications

(16 citation statements)

References 23 publications

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“…The existence of an electrochemical gradient at the BECF-ECF interface in viable bone was shown to depend on OBLCS viability (2,4,29,34,36). In fact, structural and ultrastructural analyses reported here clearly demonstrated that the osteocytes enclosed within the lacunocanalicular network and the bone lining cells (or osteoblasts) along the bone surfaces display a quite normal appearance in both unloaded and loaded metatarsals, thus confirming that all anatomical assumptions are correct.…”

Section: The Modelsupporting

confidence: 63%

Bone as an ion exchange system: evidence for a link between mechanotransduction and metabolic needs

Rubinacci

Covini

Bisogni

et al. 2002

American Journal of Physiology-Endocrinology and Metabolism

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Bone as an ion exchange system: evidence for a link between mechanotransduction and metabolic needs. Am J Physiol Endocrinol Metab 282: E851-E864, 2002. First published November 20, 2001 10.1152/ajpendo.00367.2001.-To detect whether the mutual interaction occurring between the osteocytes-bone lining cells system (OBLCS) and the bone extracellular fluid (BECF) is affected by load through a modification of the BECF-extracellular fluid (ECF; systemic extracellular fluid) gradient, mice metatarsal bones immersed in ECF were subjected ex vivo to a 2-min cyclic axial load of different amplitudes and frequencies. The electric (ionic) currents at the bone surface were measured by a vibrating probe after having exposed BECF to ECF through a transcortical hole. The application of different loads and different frequencies increased the ionic current in a dosedependent manner. The postload current density subsequently decayed following an exponential pattern. Postload increment's amplitude and decay were dependent on bone viability. Dummy and static loads did not induce current density modifications. Because BECF is perturbed by loading, it is conceivable that OBLCS tends to restore BECF preload conditions by controlling ion fluxes at the boneplasma interface to fulfill metabolic needs. Because the electric current reflects the integrated activity of OBLCS, its evaluation in transgenic mice engineered to possess genetic lesions in channels or matrix constituents could be helpful in the characterization of the mechanical and metabolic functions of bone.osteocytes; bone lining cells; mineral homeostasis; mechanical loading; fluid shear stress THE MUTUAL INTERACTION occurring between the osteocyte-bone lining cell system (OBLCS) and the surrounding bone extracellular fluid (BECF) has been suggested to play a pivotal role in bone mechanotransduction (3, 37). OBLCS is constituted by a network of stellate cells buried within the bone matrix, the osteocytes, having an asymmetrical arborization of dendrites polarized toward the bone surfaces, where they come into contact with the bone lining cells or the osteoblasts according to whether the bone is in a resting or a growing phase, respectively. Because the cells forming such a three-dimensional protoplasmic network are all joined by gap junctions, OBLCS actually constitutes a functional syncytium (24,27,26). The lacuno and canalicular network of cavities, enclosing the osteocyte cell bodies and dendrites, forms within the bone matrix a complex microstructure of pores and channels filled by BECF that has a different ionic composition from the systemic extracellular fluid (ECF) of the perivascular loose connective tissue surrounding the bone surfaces.This ionic difference is maintained by a pump-leak system that selectively operates at the OBLCS level (32, 33, 34) as a partition system (4) generating an ionic gradient between BECF and ECF (21, 22, 23, 30) with a subsequent electric potential difference at the bone membrane (36) that appears to be under parathyroid hormone control (2...

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Section: The Modelsupporting

confidence: 63%

Bone as an ion exchange system: evidence for a link between mechanotransduction and metabolic needs

Rubinacci

Covini

Bisogni

et al. 2002

American Journal of Physiology-Endocrinology and Metabolism

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“…16 Aggregates of cells also set up voltages across various tissue layers, including cutaneous and corneal epithelium, vascular and intestinal walls, and the cortex and periosteum of long bones. 14,15,[17][18][19][20][21] These voltages are of the order of millivolts (mV) in magnitude, and where there is a conducting pathway they cause the movement of ions within tissue, constituting a bioelectric current, typically in the microamp (mA) range. 14 At the cellular level, bioelectricity is involved in the transport through the membrane of ions that can influence cell behaviour.…”

Section: Introductionmentioning

confidence: 99%

Bioelectricity and microcurrent therapy for tissue healing – a narrative review

Poltawski¹,

Watson²

2009

Physical Therapy Reviews

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Background: Microcurrent therapy (MCT) uses electric currents similar to those produced by the body during tissue healing. It may be a particularly beneficial where endogenous healing has failed. Aim: To review evidence regarding microcurrent in tissue healing and the application of MCT. Methods: All peer-reviewed studies concerning microcurrent and MCT were sought, and representative literature was synthesised to indicate the scope and weight of current evidence.Results: Microcurrent appears to play a significant role in the healing process, and MCT can promote healing in a variety of bone and skin lesions. The evidence for other tissues is encouraging but presently scant. Conclusion: MCT may have unrealised potential in the treatment of dysfunctional tissue healing and deserves greater attention by researchers and clinicians.

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“…Since the tight junction is the most important barrier which restricts ion and water from passing freely through the paracellular space, the expression of tight junction proteins in osteoblasts supports the previous hypothesis that osteoblasts and bone-lining cells, which cover 90% of bone surface, form an epithelial-like bone membrane to regulate ion transport and maintain diVerential ion compositions between the plasma and BECF (Bushinsky et al 1989;Marenzana et al 2005;Peterson et al 1985;Trumbore et al 1980). Normally, concentrations of Ca 2+ , Mg 2+ and K + in BECF are approximately 0.5, 0.4 and 25 mM, whereas those in plasma are 1.25, 0.7 and 4.5 mM, respectively (Armstrong and Singer 1965;Trumbore et al 1980).…”

mentioning

confidence: 51%

“…Normally, concentrations of Ca 2+ , Mg 2+ and K + in BECF are approximately 0.5, 0.4 and 25 mM, whereas those in plasma are 1.25, 0.7 and 4.5 mM, respectively (Armstrong and Singer 1965;Trumbore et al 1980). These ionic gradients were thought to be actively maintained by bone membrane, and were dissipated in dead tissue or in the presence of inhibitors of ATP production (Marenzana et al 2005;Rubinacci et al 2002).…”

mentioning

confidence: 98%

“…The presence of TER of »110-180 cm 2 , which is comparable to the TER reported in the duodenum (Charoenphandhu et al 2006), conWrmed that the primary rat osteoblasts were able to form a functional epithelial-like membrane in vitro with the barrier property of tight junctions. In addition, other electrical parameters, i.e., PD and Isc, implicated ion Xuxes across the monolayer (Shu et al 2006;Trumbore et al 1980). Besides the barrier function, tight junctions of osteoblasts could play an important role in the vesicular traYcking of bone matrix proteins to the surface of bone and in maintaining the polarity of matrixsecreting osteoblasts, thereby resulting in an organized matrix deposition in bone tissue (Prêle et al 2003).…”

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confidence: 99%

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Osteoblasts express claudins and tight junction-associated proteins

Wongdee

Pandaranandaka

Teerapornpuntakit

et al. 2008

Histochem Cell Biol

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Osteoblasts were previously reported to form tight junctions, which may play an important role in the regulation of ion transport across the epithelial-like bone membrane. However, the evidence for the presence of tight junction-associated proteins in osteoblasts is lacking. We therefore studied the expression of tight junction-associated genes in primary rat osteoblasts and bone tissues. Quantitative real-time PCR showed that osteoblasts expressed ZO-1, -2, -3, cingulin, occludin, claudin-1 to -12, -14 to -20, -22 and -23. By using western blot analyses of selected claudins, expression of claudin-5, -11, -14 and -15, but not claudin-3, were identified in osteoblasts. A confocal immunofluorescent study in undecalcified tibial sections confirmed that claudin-16 was localized on the trabecular surface, normally covered by osteoblasts and bone-lining cells. In addition, immunohistochemical studies in decalcified tibial sections demonstrated the expression of claudin-5, -11, -14, -15 and -16 in bone-lining cells (inactive osteoblasts). Primary osteoblasts cultured in the Snapwell for 19-26 days were found to form a monolayer with measurable transepithelial resistance of approximately 110-180 Omegacm(2), confirming the presence of barrier functions of the tight junction. It was concluded that osteoblasts expressed several tight junction-associated proteins, which possibly regulated ion transport across the bone membrane.

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Electrical potential difference across bone membrane

Cited by 24 publications

References 23 publications

Bone as an ion exchange system: evidence for a link between mechanotransduction and metabolic needs

Bone as an ion exchange system: evidence for a link between mechanotransduction and metabolic needs

Bioelectricity and microcurrent therapy for tissue healing – a narrative review

Osteoblasts express claudins and tight junction-associated proteins

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