Immature tendon adaptation to strenuous exercise

1988 ◽  
Vol 65 (5) ◽  
pp. 2297-2301 ◽  
Author(s):  
S. L. Curwin ◽  
A. C. Vailas ◽  
J. Wood
Keyword(s):  
Exercise Program ◽  
Dry Weight ◽  
Treadmill Running ◽  
Strenuous Exercise ◽  
Significant Elevation ◽  
Control Groups ◽  
Cross Links ◽  
Tendon Adaptation ◽  
Fumarase Activity ◽  
Tendon Collagen

White Leghorn roosters (3 wk old) were randomly assigned to runner or control groups. Runners were subjected to a progressive treadmill running program for 8 wk, 5 days/wk at 70-80% maximal O2 consumption (VO2 max). After 8 wk, runners showed a significant elevation in gastrocnemius fumarase activity (51%) and a 21% increase in VO2max compared with controls. The exercise program induced a significant increase in tendon collagen deposition (46%) without any changes in DNA, proteoglycan, and collagen concentrations or tendon dry weight. Also, tendon collagen from runners contained fewer (50%) pyridinoline cross-links. These results suggest that high-intensity exercise causes greater matrix-collagen turnover in growing chickens, resulting in reduced maturation of tendon collagen.

Structural and mechanical adaptation of immature bone to strenuous exercise

1986 ◽  
Vol 60 (6) ◽  
pp. 2028-2034 ◽  
Author(s):  
J. J. Matsuda ◽  
R. F. Zernicke ◽  
A. C. Vailas ◽  
V. A. Pedrini ◽  
A. Pedrini-Mille ◽  
...  
Keyword(s):  
Treadmill Running ◽  
Long Bone ◽  
Strenuous Exercise ◽  
O2 Consumption ◽  
Adaptive Responses ◽  
White Leghorn ◽  
Bone Maturation ◽  
Cross Sectional ◽  
Mechanical Adaptation ◽  
Fumarase Activity

To investigate the adaptive responses of immature bone to increased loads, young (3-wk-old) White Leghorn roosters were subjected to moderately intense treadmill running for 5 or 9 wk. The training program induced significant increases in maximal O2 consumption and muscle fumarase activity in the 12-wk-old birds, demonstrating that growing chickens have the ability to enhance their aerobic capacity. The structural and mechanical properties of the runners' tarsometatarsus bones were compared with sedentary age-matched controls at 8 and 12 wk of age. Suppression of circumferential growth occurred with exercise at both ages, whereas exercise enhanced middiaphysial cortical thickening, especially on the bones' concave surfaces. Although cross-sectional area moments of inertia did not change with exercise, significant decreases in bending stiffness, energy to yield, and energy to fracture were observed. It was concluded that strenuous exercise may retard long-bone maturation, resulting in more compliant bones.

scholarly journals Role of Copper in Biosynthesis of Intramolecular Cross-links in Chick Tendon Collagen

1969 ◽  
Vol 244 (21) ◽  
pp. 5785-5789
Author(s):  
W.S. Chou ◽  
J.E. Savage ◽  
B.L. O'Dell
Keyword(s):  
Cross Links ◽  
Tendon Collagen

Skeletal muscle beta-adrenergic receptors: variations due to fiber type and training

1984 ◽  
Vol 246 (2) ◽  
pp. E160-E167 ◽  
Author(s):  
R. S. Williams ◽  
M. G. Caron ◽  
K. Daniel
Keyword(s):  
Skeletal Muscle ◽  
Adrenergic Receptors ◽  
Fiber Type ◽  
Succinic Dehydrogenase ◽  
Oxidative Capacity ◽  
Treadmill Running ◽  
Beta Adrenergic Receptors ◽  
Control Groups ◽  
Beta Adrenergic ◽  
Physiological Importance

To determine the relationship between oxidative capacity and characteristics of beta-adrenergic receptors (beta AR) in skeletal muscle, selected biochemical variables were quantitated in particulate preparations from soleus and gastrocnemius muscle from rats subjected to 10 wk of treadmill running and from three control groups: free-fed, sedentary controls; food-restricted, pair-weighted controls; and animals trained by swimming. Beta AR density and isoproterenol-stimulated adenylate cyclase activity were considerably greater in the slow-twitch oxidative soleus muscle than in the mixed fiber type gastrocnemius in animals from each group (P less than 0.005). Succinic dehydrogenase (SDH) activity of gastrocnemius was increased 23-42% (P less than 0.05) in runners over each of the control groups, concommitantly with a 15-27% increase (P less than 0.05) in beta AR density (Bmax for binding of 125I-cyanopindolol). In 24 animals from all four treatment groups, there was a significant correlation between SDH activity and beta AR density (r = 0.68; P less than 0.001). We conclude that BAR density correlates positively with oxidative capacity in skeletal muscle, but further studies are required to determine the physiological importance of these differences.

Effects of glucocorticoids and endurance training on cytochrome oxidase expression in skeletal muscle

1994 ◽  
Vol 77 (4) ◽  
pp. 1685-1690 ◽  
Author(s):  
J. R. Marone ◽  
M. T. Falduto ◽  
D. A. Essig ◽  
R. C. Hickson
Keyword(s):  
Endurance Training ◽  
Exercise Program ◽  
Treadmill Running ◽  
Female Rats ◽  
Glucocorticoid Treatment ◽  
Subunit Mrna ◽  
Mrna Content ◽  
Muscle Groups ◽  
Coordinate Changes ◽  
Fast Twitch

This investigation was undertaken to evaluate whether the mitochondrial disfunction associated with glucocorticoid treatment is expressed at the level of cytochrome-c oxidase (COX) and whether endurance training attenuates this response. Adult female rats were administered cortisol acetate (100 mg/kg body wt) or an equal volume of the vehicle solution for 11 days. Endurance training was performed by treadmill running up to 28 m/min (with intervals at 50 m/min for 2 min every 15 min), for 90 min/day, 6 days/wk, for 8–10 wk. During hormone treatments, the training animals ran every day. Exercise prevented 43–55% of the hormone-induced atrophy in various fast-twitch muscles or muscle groups. Cortisol acetate treatment produced no significant effects on COX enzyme activities or subunit mRNA content in deep red or superficial white quadriceps or mixed plantaris muscles. The levels of COX were increased as a result of training by 70–110% in plantaris and red quadriceps muscles, but no changes were seen in white quadriceps muscles. Both nuclear-encoded (COX IV) and mitochondrial-encoded (COX III) mRNAs were increased approximately twofold by the exercise program in these same muscles. These data indicate that the impaired mitochondrial functioning associated with glucocorticoids is not observed at the COX step of electron transport. The prolonged endurance-training regimen appears to induce relatively parallel increases in COX enzyme activity and mRNA expression with coordinate changes in nuclear and mitochondrial mRNAs.

Strenuous exercise decreases the percentage of type 1 T cells in the circulation

2001 ◽  
Vol 91 (4) ◽  
pp. 1708-1712 ◽  
Author(s):  
Adam Steensberg ◽  
Anders Dyhr Toft ◽  
Helle Bruunsgaard ◽  
Marie Sandmand ◽  
Jens Halkjær-Kristensen ◽  
...  
Keyword(s):  
T Cells ◽  
Peak Plasma ◽  
Maximal Oxygen Consumption ◽  
Interferon Γ ◽  
Treadmill Running ◽  
Strenuous Exercise ◽  
Plasma Epinephrine ◽  
Lymphocyte Number

Prolonged strenuous exercise is followed by a temporary functional immune impairment. Low numbers of CD4+T helper (Th) and CD8+ T cytotoxic (Tc) cells are found in the circulation. These cells can be divided according to their cytokine profile into type 1 (Th1 and Tc1), which produce interferon-γ and interleukin (IL)-2, and type 2 (Th2 and Tc2) cells, which produce IL-4. The question addressed in the present study was whether exercise affected the relative balance between the circulating levels of these cytokine-producing T cells. Nine male runners performed treadmill running for 2.5 h at 75% of maximal oxygen consumption. The intracellular expression of cytokines was detected following stimulation with ionomycin and phorbol 12-myristate 13-acetate in blood obtained before, during, and after exercise. The percentage of type 1 T cells in the circulation was suppressed at the end of exercise and 2 h after exercise, whereas no changes were found in the percentage of type 2 T cells. Plasma epinephrine correlated negatively with the percentage of circulating CD8+ T cells producing IL-2, whereas peak IL-6 correlated with the percentage of CD8+ IL-4-producing T cells in the circulation. Peak plasma IL-6 correlated with plasma cortisol postrunning. In conclusion, the postexercise decrease in T lymphocyte number is accompanied by a more pronounced decrease in type 1 T cells, which may be linked to high plasma epinephrine. Furthermore, IL-6 may stimulate type 2 T cells, thereby maintaining a relatively unaltered percentage of these cells in the circulation compared with total circulating lymphocyte number.

Magnesium substitution effect on porous scaffolds for bone repair

2011 ◽  
Vol 6 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Oana Craciunescu ◽  
Christu Tardei ◽  
Lucia Moldovan ◽  
Otilia Zarnescu
Keyword(s):  
Bone Repair ◽  
Substitution Effect ◽  
Dry Weight ◽  
Collagen Type I ◽  
Biological Properties ◽  
Porous Scaffolds ◽  
Type I ◽  
Composite Scaffolds ◽  
Cross Links ◽  
Nanocomposite Scaffolds

AbstractOf great interest in developing artificial bone is the incorporation of magnesium (Mg) ions into the ceramic lattice in order to improve the physico-chemical and structural properties of the material and to increase its morphological affinity towards newly formed osseous tissue. In the present study, we evaluated the morphological and biological properties of composite scaffolds fabricated by mixing a nanopowder of Mg-substituted beta-tricalcium phosphate with collagen type I in two dry weight ratios (variant I and II). We used biochemical methods, and electron and light microscopy to investigate their porosity, biodegradability and morphology. Osteoblast cell culture behavior in the presence of nanocomposite variants was also examined. Variant I scaffold presented a higher percentage of cross-links and a better resistance to collagenase degradation compared to variant II scaffold. Their porosity did not vary significantly. Osteoblasts cultivated in the presence of nanocomposite scaffolds for 72 h exhibited good cell viability and a normal morphology. When osteoblasts were injected into the scaffolds, a slightly higher proportion of adhered cells were observed for Mg-substituted samples after 7 days of cultivation. All these results showed that Mg-containing porous composite scaffolds had controlled degradation, allowed osteoblast proliferation and adhesion and are good candidates for bone repair.

Exercise-induced cardiac hypertrophy: a correlation of blood flow and microvasculature

1986 ◽  
Vol 60 (4) ◽  
pp. 1259-1267 ◽  
Author(s):  
E. A. Breisch ◽  
F. C. White ◽  
L. E. Nimmo ◽  
M. D. McKirnan ◽  
C. M. Bloor
Keyword(s):  
Blood Flow ◽  
Aortic Pressure ◽  
Left Ventricular ◽  
Treadmill Running ◽  
Adenosine Infusion ◽  
Strenuous Exercise ◽  
Luminal Surface ◽  
Trained Group ◽  
Cross Sectional ◽  
Maximum Exercise

The effects of exercise conditioning on the myocardium were studied in seven instrumented pigs strenuously exercised for 12 wk by treadmill running. Data were compared with eight instrumented untrained pigs. O2 consumption measured during maximum exercise effort was significantly elevated in the trained pigs (71.7 +/- 4.0 vs. 56.3 +/- 3.0 ml X ml-1 X kg-1). Absolute right and left ventricular mass increased by 20 and 13%, respectively, in response to exercise. Myocyte cross-sectional area increased by 21% in the trained hearts compared with the untrained hearts. Transmural left ventricular myocardial blood flow (ml X min-1 X g-1) was not significantly different at rest, during maximum exercise, or during exercise with adenosine infusion. However, training caused an elevation of the regional epicardial blood flow noted during exercise and exercise with adenosine. In the trained pigs mean aortic pressure during maximum exercise with adenosine infusion was not significantly different compared with untrained pigs. Coronary resistance during exercise with adenosine infusion was the same in both animal groups. In the trained group capillary numerical (no./mm2) and length (mm/mm3) densities were reduced, whereas arteriolar numerical and length densities were significantly increased compared with the untrained group. Measurements of capillary luminal surface density (mm2/mm3) in the trained group were unchanged compared with the untrained group. These results suggest that strenuous exercise does not stimulate the production of new capillaries, but this is modified by the ability of existing capillaries to increase their luminal surface area to parallel increases in myocyte growth. The arteriolar data suggest that exercise promotes the formation of new arterioles.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effect of Exercise Program on Fatigue and Depression among Geriatric Patients Undergoing Hemodialysis

2019 ◽  
Vol 8 (2) ◽  
pp. 23
Author(s):  
Soad Hassan Abd Elhameed ◽  
Doaa El Sayed Fadila
Keyword(s):  
Geriatric Patients ◽  
Controlled Trial ◽  
Geriatric Depression Scale ◽  
Depression Scale ◽  
Exercise Program ◽  
Structured Interview ◽  
University Hospital ◽  
Control Group ◽  
Control Groups ◽  
And Control

Background: Fatigue is one of the foremost common complications faced the hemodialysis elderly patients. Fatigue not only impact the daily lives and activities of patients but it conjointly influences their quality of life, which can afterwards result in magnified depression, tiny social interactions and increase dependency on others.Aim: Determine the effect of exercise program on fatigue and depression among geriatric patients undergoing hemodialysis.Design: Randomized controlled trial (pretest post-test) design was used.Setting: The study was carried out in the dialysis units of Mansoura University Hospital and New Mansoura General Hospital.Subjects: A purposive sample of 62 geriatric patients undergoing hemodialysis was selected and randomly allocated into two equal groups, study group (n = 31) and control group (n =31).Tools: Three tools were used; Structured interview questionnaire sheet, Multidimensional Fatigue Inventory Scale and Geriatric Depression Scale Short Form.Results: The mean age of the study and control groups was 63.45±4.49 and 64.7±5.25 respectively. A high statistically significant change in fatigue and depression score (pre and post 2 months) between the study and the control groups was observed (P=0.000). Moreover, a statistically significant relation was observed between fatigue and age of the hemodialysis geriatric patients after implementation of the exercise program (P= 0.002).Conclusion: Implementation of the exercise program proved to be effective in improving the level of fatigue and depression among geriatric patients undergoing hemodialysis in the study group.Recommendation: Encourage geriatric patients undergoing hemodialysis to perform regularly range of motion and relaxation exercises in order to alleviate fatigue and overcome depression.  

Effect of exercise on hormone-sensitive lipase activity in rat adipocytes

1976 ◽  
Vol 230 (2) ◽  
pp. 385-388 ◽  
Author(s):  
JA McGarr ◽  
LB Oscai ◽  
J Borensztajn
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Adipose Tissue ◽  
Free Fatty Acids ◽  
Lipase Activity ◽  
Exercise Program ◽  
Treadmill Running ◽  
Hormone Sensitive Lipase ◽  
Hormone Sensitive ◽  
Fat Pads

Hormone-sensitive lipase activity was measured in adipocytes of rats subjected to a 12-wk program of treadmill running. Enzyme activity in the runners sacrificed immediately after exercise increased 2.5-fold (P less than 0.001) in tissue exposed to epinephrine and threefold (P less than 0.001) in tissue not exposed to epinephrine, when the results were expressed per gram of adipose tissue. Increases of almost the same magnitude were observed in runners sacrificed 24 h after their last bout of work. These significant increases in enzyme activity, however, were the result of a significant reduction in the size of cells in the epididymal fat pads of the exercisers compared with those of the freely eating sedentary animals (68.7 +/- 2.7 mum vs. 82.0 +/- 2.7 mum; P less than 0.01). When the results were expressed on a per-cell basis, therefore, hormone-sensitive lipase activity, assayed in the presence or absence of epinephrine, was unaffected by the exercise program. These results provide evidence that the lipolytic capacity of adipocytes of normal, untrained rats is sufficiently large to meet the increased demand for free fatty acids imposed by the exercise program without the need for an adaptive increase in enzyme activity.

Morphometry and calcium contents in appendicular and axial bones of exercised ovariectomized rats

1985 ◽  
Vol 248 (1) ◽  
pp. R12-R17 ◽  
Author(s):  
R. L. Pohlman ◽  
L. A. Darby ◽  
A. J. Lechner
Keyword(s):  
Tensile Strength ◽  
Calcium Concentration ◽  
Exercise Program ◽  
Average Stress ◽  
Treadmill Running ◽  
Ovariectomized Rats ◽  
Moderate Exercise ◽  
Sprague Dawley ◽  
Length Of Treatment ◽  
Calcium Status

To determine the effects of exercise and ovariectomy on calcium status in selected appendicular and axial bones, female Sprague-Dawley (8-9 mo) rats were assigned to groups based on the following combinations: control (C) or ovariectomized (O); sedentary (S) or exercised (E); and length of treatment (2 or 4 mo). Exercise consisted of treadmill running for 1 h/day, 5 days/wk at a speed of 14.1 m/min and 8 degrees elevation. After death, femurs, tibia-fibula complexes, ribs (T7), and vertebrae (T7) were excised, cleaned, and weighed, and selected morphometrics were measured. Tensile strength was measured for the femurs, and all bones were then acid-hydrolyzed and calcium concentration determined spectrophotometrically. Bone [Ca2+] was significantly greater for CE and OE animals when compared with their sedentary counterparts (CS, OS). Within 4 mo calcium losses were evident in the femur and tibia of the ovariectomized animals, and the moderate exercise program was of insufficient intensity to alter this loss. The average stress to failure for femur from all groups was 1.13 +/- 0.11 N/m2. However, the effects of exercise appeared beneficial in the axial bones where [Ca2+] increased in the ovariectomized animals.

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