Tenocyte hypercellularity and vascular proliferation in a rabbit model of tendinopathy: Contralateral effects suggest the involvement of central neuronal mechanisms

Gustav Andersson, Sture Forsgen, Alexander Scott, Jamie GAIDA, Johanna Stjernfeldt, Ronny Lorentzon, Hakan Alfredson, Clas Backman, Patrik Danielson

Research output: Contribution to journalArticle

65 Citations (Scopus)

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.
Original languageEnglish
Pages (from-to)399-406
Number of pages8
JournalBritish Journal of Sports Medicine
Volume45
Issue number5
DOIs
Publication statusPublished - 2011
Externally publishedYes

Fingerprint

Tendinopathy
Blood Vessels
Rabbits
Achilles Tendon
Tendons
Vascular Endothelial Growth Factor A
Control Groups
Messenger RNA
Electric Stimulation
In Situ Hybridization
Leg
Extremities
Outcome Assessment (Health Care)
Muscles

Cite this

Andersson, Gustav ; Forsgen, Sture ; Scott, Alexander ; GAIDA, Jamie ; Stjernfeldt, Johanna ; Lorentzon, Ronny ; Alfredson, Hakan ; Backman, Clas ; Danielson, Patrik. / Tenocyte hypercellularity and vascular proliferation in a rabbit model of tendinopathy: Contralateral effects suggest the involvement of central neuronal mechanisms. In: British Journal of Sports Medicine. 2011 ; Vol. 45, No. 5. pp. 399-406.
@article{44e6e90f6c4a43b9a9658572c570e699,
title = "Tenocyte hypercellularity and vascular proliferation in a rabbit model of tendinopathy: Contralateral effects suggest the involvement of central neuronal mechanisms",
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.",
author = "Gustav Andersson and Sture Forsgen and Alexander Scott and Jamie GAIDA and Johanna Stjernfeldt and Ronny Lorentzon and Hakan Alfredson and Clas Backman and Patrik Danielson",
year = "2011",
doi = "10.1136/bjsm.2009.068122",
language = "English",
volume = "45",
pages = "399--406",
journal = "British Journal of Sports Medicine",
issn = "0306-3674",
publisher = "BMJ Publishing Group",
number = "5",

}

Tenocyte hypercellularity and vascular proliferation in a rabbit model of tendinopathy: Contralateral effects suggest the involvement of central neuronal mechanisms. / Andersson, Gustav; Forsgen, Sture; Scott, Alexander; GAIDA, Jamie; Stjernfeldt, Johanna; Lorentzon, Ronny; Alfredson, Hakan; Backman, Clas; Danielson, Patrik.

In: British Journal of Sports Medicine, Vol. 45, No. 5, 2011, p. 399-406.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Tenocyte hypercellularity and vascular proliferation in a rabbit model of tendinopathy: Contralateral effects suggest the involvement of central neuronal mechanisms

AU - Andersson, Gustav

AU - Forsgen, Sture

AU - Scott, Alexander

AU - GAIDA, Jamie

AU - Stjernfeldt, Johanna

AU - Lorentzon, Ronny

AU - Alfredson, Hakan

AU - Backman, Clas

AU - Danielson, Patrik

PY - 2011

Y1 - 2011

N2 - 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.

AB - 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.

U2 - 10.1136/bjsm.2009.068122

DO - 10.1136/bjsm.2009.068122

M3 - Article

VL - 45

SP - 399

EP - 406

JO - British Journal of Sports Medicine

JF - British Journal of Sports Medicine

SN - 0306-3674

IS - 5

ER -