Habitual side-specific loading leads to structural, mechanical and compositional changes in the patellar tendon of young and senior life-long male athletes

2021 ◽  
Author(s):  
Christian Couppé ◽  
Rene B. Svensson ◽  
Sebastian V. Skovlund ◽  
Jacob Kildevang Jensen ◽  
Christian Skou Eriksen ◽  
...  
Keyword(s):  
Patellar Tendon ◽  
Dna Content ◽  
Knee Extensor ◽  
Young Male ◽  
Cross Link ◽  
Cross Sectional ◽  
Specific Loading ◽  
3 Tesla Mri ◽  
Cross Links

Effects of life-long physical activity on tendon function have been investigated in cross-sectional studies, but these are at risk of "survivorship" bias. Here, we investigate if life-long side-specific loading is associated with greater cross-sectional area (CSA), mechanical properties, cell density (DNA content) and collagen cross-link composition of the male human patellar tendon (PT), in vivo. Nine seniors and six young male life-long elite badminton players and fencers were included. CSA of the PT obtained by 3-tesla MRI, and ultrasonography-based bilateral PT mechanics were assessed. Collagen fibril characteristics, enzymatic cross-links, non-enzymatic glycation (autofluorescence), collagen and DNA content were measured biochemically in PT biopsies. The elite athletes had a ≥15% side-to-side difference in maximal knee extensor strength, reflecting chronic unilateral sport-specific loading patterns. The PT CSA was greater on the lead extremity compared with the non-lead extremity (17 %, p=0.0001). Furthermore, greater tendon stiffness (18 %, p=0.0404) together with lower tendon stress (22 %, p=0.0005) and tendon strain (18 %, p=0.0433) were observed on the lead extremity. No effects were demonstrated from side-to-side for glycation, enzymatic cross-link, collagen, and DNA content (50%, p=0.1160). Moreover, tendon fibril density was 87±28 fibrils/μm2 on the lead extremity and 68±26 fibrils/μm2 on the non-lead extremity (28%, p=0.0544). Tendon fibril diameter was 86±14 nm on the lead extremity and 94±14 nm on the non-lead extremity (-9%, p=0.1076). These novel data suggest that life-long side-specific loading in males yields greater patellar tendon size and stiffness possibly with concomitant greater fibril density but without changes of collagen cross-link composition.

scholarly journals Cross-linking modifications of HDL apoproteins by oxidized phospholipids: structural characterization, in vivo detection, and functional implications

2020 ◽  
Vol 295 (7) ◽  
pp. 1973-1984
Author(s):  
Detao Gao ◽  
Mohammad Z. Ashraf ◽  
Lifang Zhang ◽  
Niladri Kar ◽  
Tatiana V. Byzova ◽  
...  
Keyword(s):  
Density Lipoprotein ◽  
Cross Linking ◽  
Oxidized Phospholipids ◽  
Cross Link ◽  
In Vivo Detection ◽  
Lysine Residues ◽  
Cross Links ◽  
Human Atheroma

Apolipoprotein A-I (apoA-I) is cross-linked and dysfunctional in human atheroma. Although multiple mechanisms of apoA-I cross-linking have been demonstrated in vitro, the in vivo mechanisms of cross-linking are not well-established. We have recently demonstrated the highly selective and efficient modification of high-density lipoprotein (HDL) apoproteins by endogenous oxidized phospholipids (oxPLs), including γ-ketoalkenal phospholipids. In the current study, we report that γ-ketoalkenal phospholipids effectively cross-link apoproteins in HDL. We further demonstrate that cross-linking impairs the cholesterol efflux mediated by apoA-I or HDL3 in vitro and in vivo. Using LC-MS/MS analysis, we analyzed the pattern of apoprotein cross-linking in isolated human HDL either by synthetic γ-ketoalkenal phospholipids or by oxPLs generated during HDL oxidation in plasma by the physiologically relevant MPO-H2O2-NO2− system. We found that five histidine residues in helices 5–8 of apoA-I are preferably cross-linked by oxPLs, forming stable pyrrole adducts with lysine residues in the helices 3–4 of another apoA-I or in the central domain of apoA-II. We also identified cross-links of apoA-I and apoA-II with two minor HDL apoproteins, apoA-IV and apoE. We detected a similar pattern of apoprotein cross-linking in oxidized murine HDL. We further detected oxPL cross-link adducts of HDL apoproteins in plasma and aorta of hyperlipidemic LDLR−/− mice, including cross-link adducts of apoA-I His-165–apoA-I Lys-93, apoA-I His-154–apoA-I Lys-105, apoA-I His-154–apoA-IV Lys-149, and apoA-II Lys-30–apoE His-227. These findings suggest an important mechanism that contributes to the loss of HDL's atheroprotective function in vivo.

scholarly journals The chemistry of the collagen cross-links. The characterization of Fraction C, a possible artifact produced during the reduction of collagen fibres with borohydride

1973 ◽  
Vol 135 (4) ◽  
pp. 657-665 ◽  
Author(s):  
Simon P. Robins ◽  
Allen J. Bailey
Keyword(s):  
Aldol Condensation ◽  
Condensation Product ◽  
Reduced Form ◽  
Borohydride Reduction ◽  
Cross Link ◽  
Collagen Fibres ◽  
Isolation And Identification ◽  
Cross Links

The present paper describes the isolation and identification of a major radioactive component of borotritide-reduced collagen, previously designated Fraction C. The derived structure for the compound confirms that it is identical with the ‘post-histidine’ component described by Tanzer et al. (1973) and given the trivial name histidino-hydroxymerodesmosine. Detailed studies of the effects of acid pH on the formation of Fraction C after borohydride reduction demonstrated the apparent lability of the non-reduced form, thus confirming our previous findings (Bailey & Lister, 1968). Inhibition of the formation of this component by the acid treatment appears to be due to protonation of the histidine imidazole group. Since the only new component formed on reduction of the acid-treated fibres was the reduced aldol condensation product, these results indicate that neither the histidine nor the hydroxylysine residues can be involved in covalent linkage with the aldol condensation product in the native fibre. It is suggested therefore that the proposed non-reduced aldimine form of Fraction C does not exist as an intermolecular cross-link in vivo. Thus the presence of histidino-hydroxymerodesmosine as a tetrafunctional cross-link in reduced collagen fibres is a result of a base-catalysed reaction promoted by the borohydride-reduction procedure and this component must therefore be considered as an artifact.

The In Vivo Human Patellar Tendon Mechanical And Collagen-cross-link Properties In Old And Young Men

2009 ◽  
Vol 41 ◽  
pp. 485
Author(s):  
Christian Couppe ◽  
Phillip Hansen ◽  
Mads Kongsgaard ◽  
Vuokko Kovanen ◽  
Charlotte Suetta ◽  
...  
Keyword(s):  
Patellar Tendon ◽  
Young Men ◽  
Cross Link

scholarly journals The chemistry of the collagen cross-links. The absence of reduction of dehydrolysinonorleucine and dehydrohydroxylysinonorleucine in vivo

1971 ◽  
Vol 121 (2) ◽  
pp. 257-259 ◽  
Author(s):  
A. J. Bailey ◽  
Catherine M. Peach
Keyword(s):  
Soft Tissues ◽  
Cross Link ◽  
Collagen Fibres ◽  
Cross Links

Two aldimine bonds have been shown to be present as stabilizing cross-links in intact collagen fibres from soft tissues: dehydrohydroxylysinonorleucine as a major component and dehydrolysinonorleucine being present in trace quantities. In the highly insoluble collagens less dehydrohydroxylysinonorleucine is present but the proportion of dehydrolysinonorleucine increases. In elastin the latter aldimine is reduced in vivo to give a more stable cross-link but no comparable reduction could be detected with either of the aldimines present in collagen.

scholarly journals The influence of 1-hydroxyethane-1,1-diphosphonate and dichloromethanediphosphonate on lysine hydroxylation and cross-link formation in rat bone, cartilage and skin collagen

1981 ◽  
Vol 196 (1) ◽  
pp. 303-310 ◽  
Author(s):  
H L Guenther ◽  
H E Guenther ◽  
H Fleisch
Keyword(s):  
Condensation Product ◽  
Bone Collagen ◽  
Cross Link ◽  
Skin Collagen ◽  
Cross Links ◽  
The Cross ◽  
Lysine Hydroxylation ◽  
And Cartilage ◽  
Rat Bone

The effects in vivo of dichloromethanediphosphonate and 1-hydroxyethane 1,1-diphosphonate on collagen solubility, hydroxylation of lysine and proline and on the formation of collagen intermolecular cross-links were studied by using rat bone, cartilage and skin tissues. Dichloromethanediphosphonate decreased bone collagen solubility both in acetic acid and after pepsin treatment. Although none of the diphosphonates had any effect on the hydroxylation of proline, dichloromethane-diphosphonate, but not 1-hydroxyethane-1,1-diphosphonate, increased the number of hydroxylysine residues in the alpha-chains of bone, skin and cartilage collagen. The stimulatory effect was dose-dependent. The dichloromethanediphosphonate-mediated increase in hydroxylysine residues in bone and cartilage was manifested in an increase of dihydroxylysinonorleucine, the cross-link that is formed by the condensation of two hydroxylysine residues. The cross-link hydroxylysinonorleucine, a condensation product of hydroxylysine and lysine, on the other hand, was decreased. The total number of intermolecular cross-links was not changed by the diphosphonate.

Effect of androgenic-anabolic steroids and heavy strength training on patellar tendon morphological and mechanical properties

2013 ◽  
Vol 115 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Olivier R. Seynnes ◽  
Sigitas Kamandulis ◽  
Ramutis Kairaitis ◽  
Christian Helland ◽  
Emma-Louise Campbell ◽  
...  
Keyword(s):  
Resistance Training ◽  
Patellar Tendon ◽  
Anabolic Steroids ◽  
Tendon Injury ◽  
Limit Strain ◽  
Cross Sectional ◽  
Collagen Remodeling ◽  
History Of ◽  
Androgenic Anabolic Steroids

Combined androgenic-anabolic steroids (AAS) and overloading affects tendon collagen metabolism and ultrastructure and is often associated with a higher risk of injury. The aim of this prospective study was to investigate whether such effects would be reflected in the patellar tendon properties of individuals with a history of long-term resistance training and AAS abuse (RTS group), compared with trained (RT) and untrained (CTRL) nonsteroids users. Tendon cross-sectional area (CSA), stiffness, Young's modulus, and toe limit strain were measured in vivo, from synchronized ultrasonography and dynamometry data. The patellar tendon of RT and RTS subjects was much stiffer and larger than in the CTRL group. However, stiffness and modulus were higher in the RTS group (26%, P < 0.05 and 30%, P < 0.01, respectively) than in the RT group. Conversely, tendon CSA was 15% ( P < 0.05) larger in the RT group than in RTS, although differences disappeared when this variable was normalized to quadriceps maximal isometric torque. Yet maximal tendon stress was higher in RTS than in RT (15%, P < 0.05), without any statistical difference in maximal strain and toe limit strain between groups. The present lack of difference in toe limit strain does not substantiate the hypothesis of changes in collagen crimp pattern associated with AAS abuse. However, these findings indicate that tendon adaptations from years of heavy resistance training are different in AAS users, suggesting differences in collagen remodeling. Some of these adaptations (e.g., higher stress) could be linked to a higher risk of tendon injury.

scholarly journals Influence of acetaminophen and ibuprofen on in vivo patellar tendon adaptations to knee extensor resistance exercise in older adults

2011 ◽  
Vol 111 (2) ◽  
pp. 508-515 ◽  
Author(s):  
C. C. Carroll ◽  
J. M. Dickinson ◽  
J. K. LeMoine ◽  
J. M. Haus ◽  
E. M. Weinheimer ◽  
...  
Keyword(s):  
Older Adults ◽  
Placebo Group ◽  
Resistance Training ◽  
Patellar Tendon ◽  
Signal Intensity ◽  
Knee Extensor ◽  
Older Individuals ◽  
Stiffness Modulus ◽  
Peripheral Tissues

Millions of older individuals consume acetaminophen or ibuprofen daily and these same individuals are encouraged to participate in resistance training. Several in vitro studies suggest that cyclooxygenase-inhibiting drugs can alter tendon metabolism and may influence adaptations to resistance training. Thirty-six individuals were randomly assigned to a placebo (67 ± 2 yr old), acetaminophen (64 ± 1 yr old; 4,000 mg/day), or ibuprofen (64 ± 1 yr old; 1,200 mg/day) group in a double-blind manner and completed 12 wk of knee extensor resistance training. Before and after training in vivo patellar tendon properties were assessed with MRI [cross-sectional area (CSA) and signal intensity] and ultrasonography of patellar tendon deformation coupled with force measurements to obtain stiffness, modulus, stress, and strain. Mean patellar tendon CSA was unchanged ( P > 0.05) with training in the placebo group, and this response was not influenced with ibuprofen consumption. Mean tendon CSA increased with training in the acetaminophen group (3%, P < 0.05), primarily due to increases in the mid (7%, P < 0.05) and distal (8%, P < 0.05) tendon regions. Correspondingly, tendon signal intensity increased with training in the acetaminophen group at the mid (13%, P < 0.05) and distal (15%, P = 0.07) regions. When normalized to pretraining force levels, patellar tendon deformation and strain decreased 11% ( P < 0.05) and stiffness, modulus, and stress were unchanged ( P > 0.05) with training in the placebo group. These responses were generally uninfluenced by ibuprofen consumption. In the acetaminophen group, tendon deformation and strain increased 20% ( P < 0.05) and stiffness (−17%, P < 0.05) and modulus (−20%, P < 0.05) decreased with training. These data suggest that 3 mo of knee extensor resistance training in older adults induces modest changes in the mechanical properties of the patellar tendon. Over-the-counter doses of acetaminophen, but not ibuprofen, have a strong influence on tendon mechanical and material property adaptations to resistance training. These findings add to a growing body of evidence that acetaminophen has profound effects on peripheral tissues in humans.

Aerobic exercise does not compromise muscle hypertrophy response to short-term resistance training

2013 ◽  
Vol 114 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Tommy R. Lundberg ◽  
Rodrigo Fernandez-Gonzalo ◽  
Thomas Gustafsson ◽  
Per A. Tesch
Keyword(s):  
Resistance Exercise ◽  
Muscle Hypertrophy ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Muscle Size ◽  
Mrna Levels ◽  
Cross Sectional ◽  
Before And After

This study tested the hypothesis that chronic aerobic and resistance exercise (AE+RE) would elicit greater muscle hypertrophy than resistance exercise only (RE). Ten men (25 ± 4 yr) performed 5 wk unilateral knee extensor AE+RE. The opposing limb was subjected to RE. AE completed 6 hr prior to RE consisted of ∼45 min one-legged cycle ergometry. RE comprised 4 × 7 maximal concentric-eccentric knee extensions. Various indexes of in vivo knee extensor function were measured before and after training. Magnetic resonance imaging (MRI) assessed m. quadricep femoris (QF) cross-sectional area (CSA), volume, and signal intensity (SI). Biopsies obtained from m. vastus lateralis determined fiber CSA, enzyme levels, and gene expression of myostatin, atrogin-1, MuRF-1, PGC-1α, and VEGF. Increases ( P < 0.05) in isometric strength and peak power, respectively, were comparable in AE+RE (9 and 29%) and RE (11 and 24%). AE+RE showed greater increase (14%; P < 0.05) in QF volume than RE (8%). Muscle fiber CSA increased 17% after AE+RE ( P < 0.05) and 9% after RE ( P > 0.05). QF SI increased (12%; P < 0.05) after AE+RE, but not RE. Neither AE+RE nor RE showed altered mRNA levels. Citrate synthase activity increased ( P < 0.05) after AE+RE. The results suggest that the increased aerobic capacity shown with AE+RE was accompanied by a more robust increase in muscle size compared with RE. Although this response was not carried over to greater improvement in muscle function, it remains that intense AE can be executed prior to RE without compromising performance outcome.

Mechanical properties and collagen cross-linking of the patellar tendon in old and young men

2009 ◽  
Vol 107 (3) ◽  
pp. 880-886 ◽  
Author(s):  
C. Couppé ◽  
P. Hansen ◽  
M. Kongsgaard ◽  
V. Kovanen ◽  
C. Suetta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Patellar Tendon ◽  
Structural Integrity ◽  
Young Men ◽  
Activity Level ◽  
Cross Linking ◽  
Collagen Concentration ◽  
Cross Sectional ◽  
Age Related

Age-related loss in muscle mass and strength impairs daily life function in the elderly. However, it remains unknown whether tendon properties also deteriorate with age. Cross-linking of collagen molecules provides structural integrity to the tendon fibrils and has been shown to change with age in animals but has never been examined in humans in vivo. In this study, we examined the mechanical properties and pyridinoline and pentosidine cross-link and collagen concentrations of the patellar tendon in vivo in old (OM) and young men (YM). Seven OM (67 ± 3 years, 86 ± 10 kg) and 10 YM (27 ± 2 years, 81 ± 8 kg) with a similar physical activity level (OM 5 ± 6 h/wk, YM 5 ± 2 h/wk) were examined. MRI was used to assess whole tendon dimensions. Tendon mechanical properties were assessed with the use of simultaneous force and ultrasonographic measurements during ramped isometric contractions. Percutaneous tendon biopsies were taken and analyzed for hydroxylysyl pyridinoline (HP), lysyl pyridinoline (LP), pentosidine, and collagen concentrations. We found no significant differences in the dimensions or mechanical properties of the tendon between OM and YM. Collagen concentrations were lower in OM than in YM (0.49 ± 0.27 vs. 0.73 ± 0.14 mg/mg dry wt; P < 0.05). HP concentrations were higher in OM than in YM (898 ± 172 vs. 645 ± 183 mmol/mol; P < 0.05). LP concentrations were higher in OM than in YM (49 ± 38 vs. 16 ± 8 mmol/mol; P < 0.01), and pentosidine concentrations were higher in OM than in YM (73 ± 13 vs. 11 ± 2 mmol/mol; P < 0.01). These cross-sectional data raise the possibility that age may not appreciably influence the dimensions or mechanical properties of the human patellar tendon in vivo. Collagen concentration was reduced, whereas both enzymatic and nonenzymatic cross-linking of concentration was elevated in OM vs. in YM, which may be a mechanism to maintain the mechanical properties of tendon with aging.

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