Cargando…

Aging Contributes to Inflammation in Upper Extremity Tendons and Declines in Forelimb Agility in a Rat Model of Upper Extremity Overuse

We sought to determine if tendon inflammatory and histopathological responses increase in aged rats compared to young rats performing a voluntary upper extremity repetitive task, and if these changes are associated with motor declines. Ninety-six female Sprague-Dawley rats were used in the rat model...

Descripción completa

Detalles Bibliográficos
Autores principales: Kietrys, David M., Barr-Gillespie, Ann E., Amin, Mamta, Wade, Christine K., Popoff, Steve N., Barbe, Mary F.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463562/
https://www.ncbi.nlm.nih.gov/pubmed/23056540
http://dx.doi.org/10.1371/journal.pone.0046954
_version_ 1782245307728265216
author Kietrys, David M.
Barr-Gillespie, Ann E.
Amin, Mamta
Wade, Christine K.
Popoff, Steve N.
Barbe, Mary F.
author_facet Kietrys, David M.
Barr-Gillespie, Ann E.
Amin, Mamta
Wade, Christine K.
Popoff, Steve N.
Barbe, Mary F.
author_sort Kietrys, David M.
collection PubMed
description We sought to determine if tendon inflammatory and histopathological responses increase in aged rats compared to young rats performing a voluntary upper extremity repetitive task, and if these changes are associated with motor declines. Ninety-six female Sprague-Dawley rats were used in the rat model of upper extremity overuse: 67 aged and 29 young adult rats. After a training period of 4 weeks, task rats performed a voluntary high repetition low force (HRLF) handle-pulling task for 2 hrs/day, 3 days/wk for up to 12 weeks. Upper extremity motor function was assessed, as were inflammatory and histomorphological changes in flexor digitorum and supraspinatus tendons. The percentage of successful reaches improved in young adult HRLF rats, but not in aged HRLF rats. Forelimb agility decreased transiently in young adult HRLF rats, but persistently in aged HRLF rats. HRLF task performance for 12 weeks lead to increased IL-1beta and IL-6 in flexor digitorum tendons of aged HRLF rats, compared to aged normal control (NC) as well as young adult HRLF rats. In contrast, TNF-alpha increased more in flexor digitorum tendons of young adult 12-week HRLF rats than in aged HRLF rats. Vascularity and collagen fibril organization were not affected by task performance in flexor digitorum tendons of either age group, although cellularity increased in both. By week 12 of HRLF task performance, vascularity and cellularity increased in the supraspinatus tendons of only aged rats. The increased cellularity was due to increased macrophages and connective tissue growth factor (CTGF)-immunoreactive fibroblasts in the peritendon. In conclusion, aged rat tendons were overall more affected by the HRLF task than young adult tendons, particularly supraspinatus tendons. Greater inflammatory changes in aged HRLF rat tendons were observed, increases associated temporally with decreased forelimb agility and lack of improvement in task success.
format Online
Article
Text
id pubmed-3463562
institution National Center for Biotechnology Information
language English
publishDate 2012
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-34635622012-10-09 Aging Contributes to Inflammation in Upper Extremity Tendons and Declines in Forelimb Agility in a Rat Model of Upper Extremity Overuse Kietrys, David M. Barr-Gillespie, Ann E. Amin, Mamta Wade, Christine K. Popoff, Steve N. Barbe, Mary F. PLoS One Research Article We sought to determine if tendon inflammatory and histopathological responses increase in aged rats compared to young rats performing a voluntary upper extremity repetitive task, and if these changes are associated with motor declines. Ninety-six female Sprague-Dawley rats were used in the rat model of upper extremity overuse: 67 aged and 29 young adult rats. After a training period of 4 weeks, task rats performed a voluntary high repetition low force (HRLF) handle-pulling task for 2 hrs/day, 3 days/wk for up to 12 weeks. Upper extremity motor function was assessed, as were inflammatory and histomorphological changes in flexor digitorum and supraspinatus tendons. The percentage of successful reaches improved in young adult HRLF rats, but not in aged HRLF rats. Forelimb agility decreased transiently in young adult HRLF rats, but persistently in aged HRLF rats. HRLF task performance for 12 weeks lead to increased IL-1beta and IL-6 in flexor digitorum tendons of aged HRLF rats, compared to aged normal control (NC) as well as young adult HRLF rats. In contrast, TNF-alpha increased more in flexor digitorum tendons of young adult 12-week HRLF rats than in aged HRLF rats. Vascularity and collagen fibril organization were not affected by task performance in flexor digitorum tendons of either age group, although cellularity increased in both. By week 12 of HRLF task performance, vascularity and cellularity increased in the supraspinatus tendons of only aged rats. The increased cellularity was due to increased macrophages and connective tissue growth factor (CTGF)-immunoreactive fibroblasts in the peritendon. In conclusion, aged rat tendons were overall more affected by the HRLF task than young adult tendons, particularly supraspinatus tendons. Greater inflammatory changes in aged HRLF rat tendons were observed, increases associated temporally with decreased forelimb agility and lack of improvement in task success. Public Library of Science 2012-10-03 /pmc/articles/PMC3463562/ /pubmed/23056540 http://dx.doi.org/10.1371/journal.pone.0046954 Text en © 2012 Kietrys et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Kietrys, David M.
Barr-Gillespie, Ann E.
Amin, Mamta
Wade, Christine K.
Popoff, Steve N.
Barbe, Mary F.
Aging Contributes to Inflammation in Upper Extremity Tendons and Declines in Forelimb Agility in a Rat Model of Upper Extremity Overuse
title Aging Contributes to Inflammation in Upper Extremity Tendons and Declines in Forelimb Agility in a Rat Model of Upper Extremity Overuse
title_full Aging Contributes to Inflammation in Upper Extremity Tendons and Declines in Forelimb Agility in a Rat Model of Upper Extremity Overuse
title_fullStr Aging Contributes to Inflammation in Upper Extremity Tendons and Declines in Forelimb Agility in a Rat Model of Upper Extremity Overuse
title_full_unstemmed Aging Contributes to Inflammation in Upper Extremity Tendons and Declines in Forelimb Agility in a Rat Model of Upper Extremity Overuse
title_short Aging Contributes to Inflammation in Upper Extremity Tendons and Declines in Forelimb Agility in a Rat Model of Upper Extremity Overuse
title_sort aging contributes to inflammation in upper extremity tendons and declines in forelimb agility in a rat model of upper extremity overuse
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463562/
https://www.ncbi.nlm.nih.gov/pubmed/23056540
http://dx.doi.org/10.1371/journal.pone.0046954
work_keys_str_mv AT kietrysdavidm agingcontributestoinflammationinupperextremitytendonsanddeclinesinforelimbagilityinaratmodelofupperextremityoveruse
AT barrgillespieanne agingcontributestoinflammationinupperextremitytendonsanddeclinesinforelimbagilityinaratmodelofupperextremityoveruse
AT aminmamta agingcontributestoinflammationinupperextremitytendonsanddeclinesinforelimbagilityinaratmodelofupperextremityoveruse
AT wadechristinek agingcontributestoinflammationinupperextremitytendonsanddeclinesinforelimbagilityinaratmodelofupperextremityoveruse
AT popoffsteven agingcontributestoinflammationinupperextremitytendonsanddeclinesinforelimbagilityinaratmodelofupperextremityoveruse
AT barbemaryf agingcontributestoinflammationinupperextremitytendonsanddeclinesinforelimbagilityinaratmodelofupperextremityoveruse