Epiphyseal Cartilage cAMP Changes Produced by Electrical and Mechanical Perturbations

Norton, Louis A.; Rodan, Gideon A.; Bourret, Lizabeth A.

doi:10.1097/00003086-197705000-00009

Cited by 45 publications

(34 citation statements)

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“…Mechanical stress on the articular cartilage activates chondrocytes, inducing the synthesis of proteoglycan 25) , and increasing the amounts of cAMP and cGMP 26) . Furthermore, the invasion of the subchondral bone is inhibited by transient fluid pressures such as periodic stress related to muscle contraction around the joint occurring in deep layers of the cartilage 27,28) .…”

Section: Discussionmentioning

confidence: 99%

Histopathological Changes in Knee Joint Components after Spinal Cord Injury in Rats

et al. 2012

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Abstract.[Purpose] The purpose of this study was to examine the histopathological changes in knee joint components after spinal cord injury (SCI) in rats. [Subjects and Methods] Eighteen adult, nine-week-old female Wistar rats were used in this study. Nine experimental rats underwent a spinal cord transection at the level of Th8-9 and the other nine control rats were raised normally. The animals were assessed at 1, 2 and 4 weeks after surgery. Formalin fixed sections from knee joints were morphologically examined after hematoxylin and eosin staining. Alterations of knee joint components were evaluated at four regions: the synovial membrane within the posterior articular capsule region, the cartilage apposite the femur, the cartilage apposite the tibia, and the fat pad under the patellar ligament region.[Results] Dilatation and congestion of the microvasculature and lymphoid infiltration were observed in the synovial membrane in the SCI group. These findings are similar to those found in early osteoarthritis. The surface layer of the articular cartilage in the SCI group showed fibrous proliferation. [Conclusion] The histopathological changes appear not to be progressive and may be related to spasticity of the hindlimb or a disorder in the autonomic function.

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Section: Discussionmentioning

confidence: 99%

Histopathological Changes in Knee Joint Components after Spinal Cord Injury in Rats

et al. 2012

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“…The growth plate and/ or growth plate chondrocytes also demonstrate increased cellular proliferation in vitro when exposed to various electrical signals (2,3,5,11,16,17,20,23). Attempts at stimulating the in vivo growth plate with various forms of electricity, however, either fail to demonstrate any significant increase in linear growth of the extremity in long-term studies (1,9), or else demonstrate accelerated growth but only for a brief period Of time (4).…”

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Proliferative and synthetic response of bovine growth plate chondrocytes to various capacitively coupled electrical fields

Brighton

Jensen

Pollack

et al. 1989

Journal Orthopaedic Research

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In vitro monolayer cultures of growth plate chondrocytes isolated from newborn calf costochondral junctions were subjected to capacitively coupled electrical fields for 48 h. In part A, the electrical signal was a 60-kHz sine wave applied at different voltages so as to produce electrical fields at the pericellular level of 7, 20, 50, and 126 mV/cm. Incorporations of [3H]thymidine and [35S]sulfate were assayed to determine the effect of the above fields on cells proliferation and matrix synthesis, respectively. Proliferation was increased by 47% in the 20 mV/cm field whereas the same field decreased [35S]sulfate incorporation by 21%. These changes were significant at p less than 0.05 in both instances. In part B, the 20 mV/cm field was applied in a pulsed fashion to produce daily duty cycles of 100, 25, 2, and 0.25%. Incorporation of [3H]thymidine, [35S]sulfate, and [14C]proline per DNA were assayed. Results indicated that the 100, 25, and 0.25% percent duty cycles showed significantly (p less than 0.01-0.05) increased proliferation, whereas the 0.25% signal (5 ms on/495 ms off for 6 h/day) significantly decreased [14C]proline incorporation. We conclude that the biologic response of cells in vitro is signal specific, and that the total amount of electrical energy required to stimulate the growth plate chondrocyte to increased proliferation is very small since the total time the 0.25% duty cycle signal was only 3.6 min of a 24-h period.

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“…The mechanism whereby mechanical forces and electric currents activate cells associated with bone remodeling is not fully understood, but recent observations have implicated plasma membrane-associated events and substances with the onset of cellular response to these stimuli. Essentially, three types of processes may be evoked: (1) a change in the polarity of extracellular macromolecules and/or the plasma membrane, leading to an electrochemical interaction between the membrane and these molecules [12]; (2) a change in the physical properties of the membrane, leading to an altered membrane pore size, permitting the passage of ions, such as calcium, into the cell where they activate cytoplasmic enzymes [ 13]; and (3) methylation of phospholipids, increase of membrane fluidity resulting in an increase in Ca 2+ influx, release of arachidonic acid, and synthesis of prostaglandins which increases the activity of adenylate cyclase [ 14].The cyclic nucleotides, adenosine 3',5'-monophosphate (cAMP) and guanosine 3',5'-monophosphate (cGMP), have been identified as mediators of the effects of external stimuli on bone cells in vivo [15][16][17] and in vitro [18][19][20]. Fluctuations in the levels of these substances have been found to occur in bone treated by parathyroid hormone [16] Since cyclic nucleotides and prostaglandins may be implicated as mediators and/or modulators in…”

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confidence: 99%

“…Fluctuations in the levels of these substances have been found to occur in bone treated by parathyroid hormone [16], calcitonin [ 17], and mechanical forces [ 18], as well as electric currents [19] and fields [20]. Prostaglandins, particularly those of the E and F series, have been associated with bone remodeling activities resulting from malignancies [21 ], gingival inflammation [22], rheumatic joint disease [ 23 ], mechanical stress [ 24], and fracture [25].…”

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Biochemical mediators of the effects of mechanical forces and electric currents on mineralized tissues

et al. 1984

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Cyclic nucleotides (cAMP and cGMP) and prostaglandin E (PGE) have been implicated as possible mediators of the effects of external stimuli on bone cells. The objective of this study was to determine changes in relative levels of these substances in mineralized tissue cells in response to mechanical and electrical stimuli, by the use of a combined immunohistochemical-microphotometric procedure. Canine teeth of eight 10-12 month-old female cats were tipped distally with 80 g force for either 1 h or 14 days. After 1 h, a slight elevation of staining intensity in alveolar bone osteoblasts and periodontal ligament (PDL) cells was observed at sites of tension and compression. After 14 days of treatment, this effect was markedly increased. Fifteen female cats, 10-12 months old, received electric stimulation (20 micron amperes d.c.) to the gingiva of 1 maxillary canine for 1, 5, 15, 30, or 60 min. At the cathode, significant increases of staining intensity in periosteal osteoblasts for cAMP, cGMP, and PGE were found at 15 and 60 min. At the anode, a significant rise in the staining intensity of these cells for PGE was seen at 15 min; at 60 min, cGMP and PGE, but not cAMP, were elevated. These results demonstrate the usefulness of the immunohistochemical technique in detecting relative changes in mineralized tissue cell content of cyclic nucleotides and prostaglandins in response to local application of physical stimuli of short and long duration.

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Epiphyseal Cartilage cAMP Changes Produced by Electrical and Mechanical Perturbations

Cited by 45 publications

References 0 publications

Histopathological Changes in Knee Joint Components after Spinal Cord Injury in Rats

Histopathological Changes in Knee Joint Components after Spinal Cord Injury in Rats

Proliferative and synthetic response of bovine growth plate chondrocytes to various capacitively coupled electrical fields

Biochemical mediators of the effects of mechanical forces and electric currents on mineralized tissues

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