Effect of eccentric exercise on the healing process of injured patellar tendon in rats

Nakamura, Kenichi; Kitaoka, Katsuhiko; Tomita, Katsuro

doi:10.1007/s00776-008-1242-6

Cited by 17 publications

(24 citation statements)

References 24 publications

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“…Changes in tendon vascularization have also been accounted for by others as partially an adaptation to exercise, which is induced by an increased VEGF expression (Gavin and Wagner, 2001;Pufe et al, 2005;Nakamura et al, 2008). As MMP-2 activity is frequently associated with the process of angiogenesis in several tissues (Lafleur et al, 2003;Rundhaug, 2005), the activation of MMP-2 after exercise observed herein may also be related to changes in blood vessel volume fraction at peritendinous sheath.…”

Section: Discussionsupporting

confidence: 51%

Calcaneal Tendon Regions Exhibit Different MMP‐2 Activation After Vertical Jumping and Treadmill Running

Malheiro

Giacomini

Justulin

et al. 2009

The Anatomical Record

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Increased activity of matrix metalloproteinases (MMPs) -2 and -9 was found in calcaneal tendon after physical training. However, little attention has been given to the distinct biomechanical and tissue structure of the calcaneal tendon's proximal and distal regions. Herein, we evaluated the effect of two types of physical activities on tendon morphology and matrix metalloproteinase activities in the proximal and distal regions of rat calcaneal tendon, separately. Adult male Wistar rats from control, water-adapted, vertical-jumping, and treadmill-running groups were sacrificed after 1 or 4 days of physical exercise, 6 hr after the end of that day's exercise session. Tendons were processed for histology, morphometry, and gelatin zymography. Tendons from adapted and trained animals showed active secretory cells and increased thickness, cellularity, and blood vessel volume fraction of peritendinous sheath, but without inflammatory process. In the proximal region, both pro-and active MMP-2 were increased after vertical jumping, but only pro-MMP-2 was increased after treadmill running. In contrast, in the distal region, both exercise types increased the activity of pro-and active MMP-2, especially treadmill running, which increased the active MMP-2 by about 11-and eightfold, respectively, after 1 and 4 days of training. No activity of MMP-9 was observed in either tendon region in this study. In conclusion, distal and proximal regions of calcaneal tendon exhibit differential intensities of tissue remodeling after treadmill running or vertical jumping and MMP-2, in the absence of inflammation, plays a major role in this adaptive response.

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Section: Discussionsupporting

confidence: 51%

Calcaneal Tendon Regions Exhibit Different MMP‐2 Activation After Vertical Jumping and Treadmill Running

Malheiro

Giacomini

Justulin

et al. 2009

The Anatomical Record

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“…The efficacy of laser therapy on the behavior of angiogenesis had already been mentioned by Lins et al (2010), who reviewed the biostimulation effects of low-level laser on the tissue repair process. However, during this process, increased vascularity is initially expected, which should be followed by a subsequent reduction (Nakamura et al 2008). This was exactly what occurred in animals that had been treated only with laser therapy.…”

Section: Discussionmentioning

confidence: 95%

“…According to Orhan et al (2004), the appearance of adhesions depends on the degree of mobilization of the tendon during the healing period. With regard to the controlled physical activity, Nakamura et al (2008) reported that physical exercise is essential for the recovery of the tendon, since it contributes to the realignment of tendon fibers. Additionally, it has been demonstrated that the immobilization of the limb may affect the biomechanical properties of the tendon (Wren et al 2000).…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, the decision to begin physical activity after one day of tendinopathy induction was aimed at standardizing the time of initiation of the treatment, as laser therapy should be initiated within the first hours after tendon injury because of its analgesic and anti-inflammatory effects. This time was considered ideal for starting the exercise, based on the protocol described by Nakamura et al (2008), who observed a beneficial effect of downhill running initiated 24h after surgical induction of tendinopathy of the patellar tendon of rats. However, unlike the findings of those authors, Godbout et al (2006) reported that physical activity performed voluntarily (running wheel inside the cages, linked to an automatic counter) may have a negative effect, such as the extended inflammatory phase.…”

Section: Discussionmentioning

confidence: 99%

“…During three weeks, a treadmill (Insight Pesquisa e Ensino Ltda) walking protocol modified from that described by Nakamura et al (2008), who used eccentric exercise (downhill treadmill running) for a longer period (60min) and at a higher speed (15m/min), was adopted. With the purpose of prior adaptation to the exercise, the animals were exercised for seven consecutive days before surgical injury induction.…”

Section: Methodsmentioning

confidence: 99%

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Histomorphometric analysis of the Achilles tendon of Wistar rats treated with laser therapy and eccentric exercise

Souza

Moreira²,

Silva³

et al. 2015

Pesq. Vet. Bras.

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Low-level laser therapy is recommended for the treatment of tendinopathies despite the contradictory results related to the ideal dose of energy, wavelength and time of application. This study aimed to assess the effects of laser therapy and eccentric exercise on tendinopathy of the Achilles tendon of Wistar rats. Forty-eight adult male rats were randomly distributed into four groups (L= laser; E= eccentric exercise; LE = laser and eccentric exercise; and R= rest). Laser therapy (904nm/3J/cm²) and/or eccentric exercise (downhill walking; 15 o incline treadmill; 12m/min; 50min/day) was started 24h after induction of unilateral tendinopathy and remained for 20 days. At 3, 7, 14 and 21 days after lesion induction, three rats from each group were euthanized and the tendons were collected for histological and morphometric analyses. There was no difference among groups or among times for the characteristics hemorrhage (p=0.4154), fibrinous adhesion formation (p=0.0712), and organization of collagen fibers (p=0.2583) and of the connective tissue (p=0.1046). For these groups, regardless of the time, eccentric exercise led to epitenon thickening (p=0.0204), which was lower in the group treated with laser therapy. Histological analysis revealed differences (p=0.0032) in the number of inflammatory cells over time. They were more numerous in the group that only exercised. This result was confirmed by morphometric analysis, which showed a significant interaction (groups x time) for this characteristic. Eccentric exercise increased (p=0.0014) the inflammatory infiltrate over time (3 and 21 days). However, association with laser therapy reduced inflammatory reaction. On the other hand, the combination of the treatments increased angiogenesis in morphometric (p=0.0000) and histological (p=0.0006) analyses compared with the other groups, while the isolated application of low-level laser reduced this characteristic over time. Animals maintained at rest presented the lowest amount (p=0.0000) of fibroblasts, according to the morphometric analysis. However, histological evaluation showed a significant group x time interaction (p=0.0024). Greater amounts of fibroblasts were observed in groups E, L and LE on the 7 th , 14 th and 21 st days, respectively. The animals that received laser therapy and were exercised showed a greater (p=0.0000) amount of collagen fibers over time. LE=laser e exercício excêntrico, e R=repouso). Após 24h da indução de tendinopatia unilateral, foi iniciada laserterapia (904nm/3J/cm²) e/ou exercício excêntrico (caminhada em declive; esteira com 15 o de inclinação; 12m/min; 50min/ dia) que permaneceu por 20 dias. Aos 3, 7, 14 e 21 dias após indução da lesão, três ratos de cada grupo foram submetidos à eutanásia, e os tendões foram obtidos para análi-ses histológica e morfométrica. Não houve diferença entre grupos nem entre tempos nas características hemorragia (p=0,4154), formação de aderência fibrinosa (p=0,0712) e organização das fibras colágenas (p=0,2583) e do tecido conjuntivo (p=0,1046). Considerando os g...

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Role of angiogenesis after muscle derived stem cell transplantation in injured medial collateral ligament

Nishimori

Matsumoto

Ota

et al. 2011

Journal Orthopaedic Research

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We performed this study to investigate the therapeutic role of vascular endothelial growth factor (VEGF) in medial collateral ligament (MCL) healing. Murine muscle derived stem cells (MDSCs) obtained via the preplate technique were retrovirally transduced to express: (1) VEGF and nLacZ (MDSC-VEGF), (2) soluble fms-like tyrosine kinase-1 (sFLT1, a VEGF-specific antagonist) and nLacZ (MDSC-sFLT1), and (3) nLacZ (MDSC-nLacZ). After transecting the MCL of immunodeficient rats, 5 Â 10 5 cells of each of the transduction groups list above were transplanted into the MCL injury site. A control group was injected with phosphate-buffered saline (PBS) only. Immunohistochemical staining demonstrated that there were more Isolectin B4 and b-galactosidase double positive cells in the rats transplanted with MDSC-VEGF transduced cells than the other groups at week 1. Capillary density was significantly higher in the MDSC-VEGF group than the other groups at week 2; however, there were no significant differences in the biomechanical assessment between the MDSC-VEGF and MDSC-nLacZ groups. On the other hand, the MDSC-sFLT1 group revealed a lower capillary density than the other two groups and the functional ligament healing of the MDSC-sFLT1 group was significantly decreased compared to the other groups when assessed biomechanically. The findings of the present study suggest that angiogenesis plays a critical role in the healing process of injured MCL. ß

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Effect of eccentric exercise on the healing process of injured patellar tendon in rats

Cited by 17 publications

References 24 publications

Calcaneal Tendon Regions Exhibit Different MMP‐2 Activation After Vertical Jumping and Treadmill Running

Calcaneal Tendon Regions Exhibit Different MMP‐2 Activation After Vertical Jumping and Treadmill Running

Histomorphometric analysis of the Achilles tendon of Wistar rats treated with laser therapy and eccentric exercise

Role of angiogenesis after muscle derived stem cell transplantation in injured medial collateral ligament

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