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- Andersson, Gustav, et al.
(författare)
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Substance P accelerates hypercellularity and angiogenesis in tendon tissue and enhances paratendinitis in response to Achilles tendon overuse in a tendinopathy model
- 2011
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Ingår i: British Journal of Sports Medicine. - Loughborough : British Assoc. of Sport and Medicine. - 0306-3674 .- 1473-0480. ; 45:13, s. 1017-1022
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Tidskriftsartikel (refereegranskat)abstract
- Background Tenocytes produce substance P (SP) and its receptor (neurokinin-1 receptor (NK-1R) is expressed throughout the tendon tissue, expecially in patients with tendinopathy and tissue changes (tendinosis) including hypercellularity and vascular proliferation. Considering the known effects of SP, one might ask whether SP contributes to these canges.Objectives To test whether development of tendinosislike changes (hypercellularity and angiogenesis) is accelerated during a 1-week course of ecercise with local administration of SP in an establish Achilles tendinopathy model.Methods Rabbits were subjected to a protocol of Achilles tendon overuse for 1 week, in conjunction with SP injections in the paratenon. Exercised control animals received NaCl injections or no injections, and unexercised, uninjected controls were also used. Tenocyte number and vascular density, as well as paratendinous inflammation, were evaluated. Immunohistochemistry and in sity hybridisation to detect NK-1R were conducted.Results There was a significant increase in tenocyte number in the SP-injected and NaCl-injected groups compared with both unexercised and exercised, uninjected controls. Tendon blood vessels increased in number in the SP-injected group compared with unexercised controls, a finding not seen in NaCl-injected controls or in uninjected, exercised animals. Paratendinous inflammation was more pronounced in the SP-injected group than in the NaCl controls. NK-1R was detected in blood vessel walls, nerves, inflammatory cells and tenocytes.Conclusions SP accelerated the development of tendinosis-like changes in the rabbit. Achilles tendon, which supports theories of a potential role of SP in tendinosis development; a fact of clinical interest since SP effects can be effectively blocked. The angiogenic response to SP injections seems related to parateninitis.
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| 2. |
- Andersson, Gustav, 1983-, et al.
(författare)
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Tenocyte hypercellularity and vascular proliferation in a rabbit model of tendinopathy : contralateral effects suggest the involvement of central neuronal mechanisms
- 2011
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Ingår i: British Journal of Sports Medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 45:5, s. 399-406
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Tidskriftsartikel (refereegranskat)abstract
- Objective To determine whether there are objective findings of tendinosis in a rabbit tendinopathy model on exercised and contralateral (non-exercised) Achilles tendons. Design Four groups of six New Zealand white rabbits per group were used. The animals of one (control) group were not subjected to exercise/stimulation. Interventions Animals were subjected to a protocol of electrical stimulation and passive flexion-extension of the right triceps surae muscle every second day for 1, 3 or 6 weeks. Main Outcome Measures Tenocyte number and vascular density were calculated. Morphological evaluations were also performed as well as in-situ hybridisation for vascular endothelial growth factor (VEGF) messenger RNA. Results There was a significant increase in the tenocyte number after 3 and 6 weeks of exercise, but not after 1 week, in comparison with the control group. This was seen in the Achilles tendons of both legs in experimental animals, including the unexercised limb. The pattern of vascularity showed an increase in the number of tendon blood vessels in rabbits that had exercised for 3 weeks or more, compared with those who had exercised for 1 week or not at all. VEGF-mRNA was detected in the investigated tissue, with the reactions being more clearly detected in the tendon tissue with tendinosis-like changes (6-week rabbits) than in the normal tendon tissue (control rabbits). Conclusions There were bilateral tendinosis-like changes in the Achilles tendons of rabbits in the current model after 3 weeks of training, suggesting that central neuronal mechanisms may be involved and that the contralateral side is not appropriate as a control.
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| 3. |
- Backman, Ludvig J., et al.
(författare)
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Substance P reduces TNF-α-induced apoptosis in human tenocytes through NK-1 receptor stimulation
- 2014
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Ingår i: British Journal of Sports Medicine. - : BMJ Publishing Group Ltd. - 0306-3674 .- 1473-0480. ; 48:19, s. 1414-1420
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: It has been hypothesised that an upregulation of the neuropeptide substance P (SP) and its preferred receptor, the neurokinin-1 receptor (NK-1 R), is a causative factor in inducing tenocyte hypercellularity, a characteristic of tendinosis, through both proliferative and antiapoptotic stimuli. We have demonstrated earlier that SP stimulates proliferation of human tenocytes in culture.AIM: The aim of this study was to investigate whether SP can mediate an antiapoptotic effect in tumour necrosis factor-α (TNF-α)-induced apoptosis of human tenocytes in vitro.RESULTS: A majority (approximately 75%) of tenocytes in culture were immunopositive for TNF Receptor-1 and TNF Receptor-2. Exposure of the cells to TNF-α significantly decreased cell viability, as shown with crystal violet staining. TNF-α furthermore significantly increased the amount of caspase-10 and caspase-3 mRNA, as well as both BID and cleaved-poly ADP ribosome polymerase (c-PARP) protein. Incubation of SP together with TNF-α resulted in a decreased amount of BID and c-PARP, and in a reduced lactate dehydrogenase release, as compared to incubation with TNF-α alone. The SP effect was blocked with a NK-1 R inhibitor.DISCUSSION: This study shows that SP, through stimulation of the NK-1 R, has the ability to reduce TNF-α-induced apoptosis of human tenocytes. Considering that SP has previously been shown to stimulate tenocyte proliferation, the study confirms SP as a potent regulator of cell-turnover in tendon tissue, capable of stimulating hypercellularity through different mechanisms. This gives further support for the theory that the upregulated amount of SP seen in tendinosis could contribute to hypercellularity.
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| 4. |
- Danielson, Patrik
(författare)
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Reviving the "biochemical" hypothesis for tendinopathy : new findings suggest the involvement of locally produced signal substances
- 2009
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Ingår i: British Journal of Sports Medicine. - : BMJ Publishing Group. - 0306-3674 .- 1473-0480. ; 43:4, s. 265-268
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Tidskriftsartikel (refereegranskat)abstract
- Studies of recent years on human tendinopathies have provided us with evidence of a local, non-neuronal production in tendon cells (tenocytes) of signal substances traditionally confined to neurons. These substances include acetylcholine, catecholamines, substance P, and glutamate. Furthermore, the receptors for several of these substances have been found on nerve fascicles and in blood vessel walls, as well as on the tenocytes themselves, of the tendon tissue. The findings provide the basis for locally produced signal substances to influence pain signaling, vascular regulation, and/or tissue changes in tendinopathy. This reinforces a previously presented "biochemical" hypothesis for tendinopathy, suggesting that biochemical mediators in the tendon tissue might influence/irritate nociceptors, in or around the tendon, to cause chronic tendon pain. The potential clinical implications of the studies are considerable.
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| 5. |
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| 6. |
- Scott, Alex, et al.
(författare)
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Sports and exercise-related tendinopathies : a review of selected topical issues by participants of the second International Scientific Tendinopathy Symposium (ISTS) Vancouver 2012
- 2013
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Ingår i: British Journal of Sports Medicine. - London, England : BMJ Publishing Group. - 0306-3674 .- 1473-0480. ; 47:9, s. 536-
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Tidskriftsartikel (refereegranskat)abstract
- In September 2010, the first International Scientific Tendinopathy Symposium (ISTS) was held in Umea, Sweden, to establish a forum for original scientific and clinical insights in this growing field of clinical research and practice. The second ISTS was organised by the same group and held in Vancouver, Canada, in September 2012. This symposium was preceded by a round-table meeting in which the participants engaged in focused discussions, resulting in the following overview of tendinopathy clinical and research issues. This paper is a narrative review and summary developed during and after the second ISTS. The document is designed to highlight some key issues raised at ISTS 2012, and to integrate them into a shared conceptual framework. It should be considered an update and a signposting document rather than a comprehensive review. The document is developed for use by physiotherapists, physicians, athletic trainers, massage therapists and other health professionals as well as team coaches and strength/conditioning managers involved in care of sportspeople or workers with tendinopathy.
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| 7. |
- Zeisig, Eva, et al.
(författare)
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Immunohistochemical evidence of local production of catecholamines in cells of the muscle origins at the lateral and medial humeral epicondyles : of importance for the development of tennis and golfer's elbow?
- 2009
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Ingår i: British Journal of Sports Medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 43:4, s. 269-275
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Tennis elbow (TE) is a painful condition affecting the common extensor origin at the lateral humeral epicondyle. Colour Doppler examination has shown increased blood flow at this site and the sensory, and sympathetic innervation patterns have been delineated. However, it is not known whether there is local production of catecholamines and/or acetylcholine in this tissue, which is the case in patellar and Achilles tendinopathies. OBJECTIVE: To investigate the possible presence of local production of catecholamines and acetylcholine in non-neuronal cells (fibroblasts) in connective tissue at the muscle origin at the lateral humeral epicondyle in patients with TE. DESIGN: Immunohistochemical studies were performed on biopsies taken from the extensor origin in patients with TE and in pain-free controls. For reference purpose, biopsies from the flexor origin in patients with golfer's elbow (GE) were also studied. PATIENTS: Seven patients with TE and four patients with GE. Six healthy asymptomatic individuals served as controls. Method: Immunohistochemistry, using antibodies detecting synthesising enzymes for catecholamines (tyrosine hydroxylase; TH) and acetylcholine (choline acetyltransferase; ChAT). RESULTS: TH-like immunohistochemical reactions were seen in fibroblasts in four of the seven patients with TE and two of the four patients with GE. No such reactions were detected in controls (0/6). No ChAT reactions were seen in any of the investigated specimens. CONCLUSIONS: There is evidence of local, non-neuronal production of catecholamines, but not acetylcholine, in fibroblasts in the tissue at the muscle origin at the lateral and medial epicondyles in patients with TE and GE, respectively, which might have an influence on blood vessel regulation and pain mechanisms in these conditions.
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