scholarly journals ACETAMINOPHEN CONSUMPTION ALTERS ACHILLES TENDON COLLAGEN CONTENT IN WISTAR RATS

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Jamie A Whitt ◽  
Jamie Tedeschi ◽  
David R McMullan ◽  
Jonathan D Del Mundo ◽  
Tom L Broderick ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Wistar Rats ◽  
Collagen Content ◽  
Tendon Collagen

Influence of acetaminophen consumption and exercise on Achilles tendon structural properties in male Wistar rats

2012 ◽  
Vol 302 (8) ◽  
pp. R990-R995 ◽  
Author(s):  
Chad C. Carroll ◽  
Jamie A. Whitt ◽  
Amity Peterson ◽  
Brian S. Gump ◽  
Jamie Tedeschi ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Water Content ◽  
High Performance ◽  
Wistar Rats ◽  
Collagen Content ◽  
Cross Linking ◽  
Tissue Water ◽  
Tendon Stiffness ◽  
Main Effect ◽  
Male Wistar Rats

Chronic consumption of acetaminophen (APAP) during exercise training leads to a reduction in tendon stiffness and modulus compared with a placebo. We explored whether this effect could be due to a reduction in tendon collagen content or cross-linking. Ten-week-old male Wistar rats ( n = 50) were divided into placebo or APAP groups and into sedentary or treadmill-exercised groups. APAP (200 mg/kg) or saline was administered once daily by oral gavage. Rats in the exercise groups ran on a treadmill 5 days per week for 8 wk with progression to 60 min per day, 20 m/min, and 8° incline. After 8 wk, lyophilized Achilles tendon samples were assayed for the collagen-specific amino acid hydroxyproline and cross-linking [hydroxylyslpyridinoline (HP)] content by high-performance liquid chromatrography. Collagen content was not influenced by exercise or APAP ( P > 0.05). Compared with placebo, tendon water content was 7% ( P = 0.006, main effect) lower in animals consuming APAP (placebo: 54.79 ± 0.8%, APAP: 50.89 ± 1.2%). HP in the Achilles tendon was 36% greater (sedentary: 141 ± 15, exercise: 204 ± 26 mmol/mol collagen) in the exercise-trained rats independent of drug treatment ( P = 0.020, main effect). Independent of exercise, HP content was 33% lower ( P = 0.032, main effect) in the animals consuming APAP (placebo: 195 ± 21, APAP: 140 ± 19 mmol/mol collagen). Our data suggests that chronic consumption of APAP results in a reduction in collagen cross-linking and a loss of tissue water independent of chronic exercise. This reduction in cross-linking and water content could contribute to the decrease in tendon stiffness noted in humans chronically consuming APAP.

scholarly journals EFFECTS OF EXERCISE TRAINING ON BACK SKIN AND ACHILLES TENDON COLLAGEN CONTENT IN GROWING MICE

1988 ◽  
Vol 37 (4) ◽  
pp. 303-307
Author(s):  
KENZO KOYAMA ◽  
NORIKO OMICHI ◽  
HIROSHI KOGAWA ◽  
MASANA NAKAI ◽  
EIJI GOTO
Keyword(s):  
Exercise Training ◽  
Achilles Tendon ◽  
Collagen Content ◽  
Tendon Collagen

scholarly journals The soy isoflavone genistein inhibits the reduction in Achilles tendon collagen content induced by ovariectomy in rats

2012 ◽  
Vol 22 (5) ◽  
pp. e108-e114 ◽  
Author(s):  
J. E. Ramos ◽  
L. Al-Nakkash ◽  
A. Peterson ◽  
B. S. Gump ◽  
T. Janjulia ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Collagen Content ◽  
Soy Isoflavone ◽  
Tendon Collagen

scholarly journals Local treatment with ascorbic acid accelerates recovery of post-sutured Achilles tendon in male Wistar rats

2019 ◽  
Vol 52 (9) ◽  
Author(s):  
M. Souza ◽  
S.A.S. Moraes ◽  
D.R. de Paula ◽  
A.A. Maciel ◽  
E.J.O. Batista ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Achilles Tendon ◽  
Wistar Rats ◽  
Local Treatment ◽  
Male Wistar Rats

scholarly journals Influence of acute and chronic streptozotocin-induced diabetes on the rat tendon extracellular matrix and mechanical properties

2015 ◽  
Vol 309 (9) ◽  
pp. R1135-R1143 ◽  
Author(s):  
Brent D. Volper ◽  
Richard T. Huynh ◽  
Kathryn A. Arthur ◽  
Joshua Noone ◽  
Benjamin D. Gordon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Patellar Tendon ◽  
Collagen Content ◽  
Control Group ◽  
Diabetic Patients ◽  
Insulin Group ◽  
Chronic Group ◽  
Acute Group ◽  
Streptozotocin Induced Diabetes

Diabetes is a major risk factor for tendinopathy, and tendon abnormalities are common in diabetic patients. The purpose of the present study was to evaluate the effect of streptozotocin (60 mg/kg)-induced diabetes and insulin therapy on tendon mechanical and cellular properties. Sprague-Dawley rats ( n = 40) were divided into the following four groups: nondiabetic (control), 1 wk of diabetes (acute), 10 wk of diabetes (chronic), and 10 wk of diabetes with insulin treatment (insulin). After 10 wk, Achilles tendon and tail fascicle mechanical properties were similar between groups ( P > 0.05). Cell density in the Achilles tendon was greater in the chronic group compared with the control and acute groups (control group: 7.8 ± 0.5 cells/100 μm2, acute group: 8.3 ± 0.4 cells/100 μm2, chronic group: 10.9 ± 0.9 cells/100 μm2, and insulin group: 9.2 ± 0.8 cells/100 μm2, P < 0.05). The density of proliferating cells in the Achilles tendon was greater in the chronic group compared with all other groups (control group: 0.025 ± 0.009 cells/100 μm2, acute group: 0.019 ± 0.005 cells/100 μm2, chronic group: 0.067 ± 0.015, and insulin group: 0.004 ± 0.004 cells/100 μm2, P < 0.05). Patellar tendon collagen content was ∼32% greater in the chronic and acute groups compared with the control or insulin groups (control group: 681 ± 63 μg collagen/mg dry wt, acute group: 938 ± 21 μg collagen/mg dry wt, chronic: 951 ± 52 μg collagen/mg dry wt, and insulin group: 596 ± 84 μg collagen/mg dry wt, P < 0.05). In contrast, patellar tendon hydroxylysyl pyridinoline cross linking and collagen fibril organization were unchanged by diabetes or insulin ( P > 0.05). Our findings suggest that 10 wk of streptozotocin-induced diabetes does not alter rat tendon mechanical properties even with an increase in collagen content. Future studies could attempt to further address the mechanisms contributing to the increase in tendon problems noted in diabetic patients, especially since our data suggest that hyperglycemia per se does not alter tendon mechanical properties.

Degradation of bovine achilles tendon collagen byCandida albicansproteinase

1988 ◽  
Vol 26 (5) ◽  
pp. 315-318 ◽  
Author(s):  
H. Kaminishi ◽  
Y. Hagihara ◽  
M. Tanaka ◽  
T. Cho
Keyword(s):  
Achilles Tendon ◽  
Tendon Collagen

Automatic Evaluation of Collagen Fiber Directions from Polarized Light Microscopy Images

2015 ◽  
Vol 21 (4) ◽  
pp. 863-875 ◽  
Author(s):  
Kamil Novak ◽  
Stanislav Polzer ◽  
Michal Tichy ◽  
Jiri Bursa
Keyword(s):  
Light Microscopy ◽  
Achilles Tendon ◽  
Collagen Fiber ◽  
Polarized Light ◽  
Polarized Light Microscopy ◽  
Collagen Content ◽  
Aortic Tissue ◽  
Collagen Orientation ◽  
Automated Method ◽  
Microscopy Images

AbstractMechanical properties of the arterial wall depend largely on orientation and density of collagen fiber bundles. Several methods have been developed for observation of collagen orientation and density; the most frequently applied collagen-specific manual approach is based on polarized light (PL). However, it is very time consuming and the results are operator dependent. We have proposed a new automated method for evaluation of collagen fiber direction from two-dimensional polarized light microscopy images (2D PLM). The algorithm has been verified against artificial images and validated against manual measurements. Finally the collagen content has been estimated. The proposed algorithm was capable of estimating orientation of some 35 k points in 15 min when applied to aortic tissue and over 500 k points in 35 min for Achilles tendon. The average angular disagreement between each operator and the algorithm was −9.3±8.6° and −3.8±8.6° in the case of aortic tissue and −1.6±6.4° and 2.6±7.8° for Achilles tendon. Estimated mean collagen content was 30.3±5.8% and 94.3±2.7% for aortic media and Achilles tendon, respectively. The proposed automated approach is operator independent and several orders faster than manual measurements and therefore has the potential to replace manual measurements of collagen orientation via PLM.

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

2015 ◽  
Vol 35 (suppl 1) ◽  
pp. 39-50
Author(s):  
Maria V. de Souza ◽  
José do C.L. Moreira ◽  
Micheline O. da Silva ◽  
Júlio Crepaldi ◽  
Carlos Henrique Osório Silva ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Laser Therapy ◽  
Eccentric Exercise ◽  
Morphometric Analysis ◽  
Wistar Rats ◽  
Inflammatory Infiltrate ◽  
Collagen Fibers ◽  
The Other ◽  
Level Laser ◽  
Over Time

Abstract: 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; 15o 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 7th, 14th and 21st days, respectively. The animals that received laser therapy and were exercised showed a greater (p=0.0000) amount of collagen fibers over time. Laser therapy at a dose of 3J and at a wavelength of 904nm, starting 24h after surgical induction of tendinopathy in Wistar rats, is suitable for angiogenesis and prevention of tendon thickening, which can be associated with the intensity of inflammatory process. When associated with eccentric exercise, the therapy has the advantage of increasing the amount of collagen fibers, reducing fibrinous adhesions and inflammatory infiltrate, despite prolonging angiogenesis. Therefore, eccentric exercise performed concomitantly with laser therapy improves the histological properties of the injured tendon.

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