Exercise training attenuates aging-associated increases in collagen and collagen crosslinking of the left but not the right ventricle in the rat

Thomas, D. P.; Cotter, Thusitha; Li, X; McCormick, Richard J.; Gosselin, Luc E.

doi:10.1007/s004210100447

Cited by 62 publications

(59 citation statements)

References 33 publications

(56 reference statements)

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“…2) LV ANF expression is increased several fold in response to hypertrophic stimuli in animals of either sex (13,(16)(17)(18)21,22,32,60,61); the increase in ANF expression in response to a hypertrophic stimulus is typically greater in magnitude than the gender differences in ANF expression (62); differences among rat strains in ventricular ANF expression are greater than gender differences (57). 3) Increases in expression of extracellular matrix components are reported for animals of both sexes with no gender differences in the magnitude of response (62), but not in response to exercise in either sex (53)(54)(55)63). 4) Examination of the present data with respect to sex differences did not reveal any within-group anomalies as a function of sex.…”

Section: Discussionmentioning

confidence: 99%

Effects of gradual coronary artery occlusion and exercise training on gene expression in swine heart

et al. 2006

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Gradual occlusion (O) of the swine left circumflex coronary artery (LCX) with an ameroid occluder results in complete O within 3 weeks, collateral vessel development, and compensatory hypertrophy. The purpose of this investigation was to determine the independent and combined effects of O and exercise training (E) on gene expression in the swine heart. Adult Yucatan miniature swine were assigned to one of the following groups (n = 6-9/group): sedentary control (S), exercise-trained (E), sedentary swine subjected to LCX occlusion (SO), and exercise-trained swine with LCX occlusion (EO). Exercise consisted of progressive treadmill running conducted 5 d/wk for 16 weeks. Gene expression was studied in myocardium isolated from the collateral-dependent left ventricle free wall (LV) and the collateral-independent septum (SEP) by RNA blotting. E and O each stimulated cardiac hypertrophy independently (p < 0.001) with no interaction. O but not E increased atrial natriuretic factor expression in the LV, but not in the SEP. E decreased the expression of β-myosin heavy chain in the LV, but not in the SEP. E retarded the expression of collagen III mRNA in SEP; but not in the LV. Exercise training and coronary artery occlusion each stimulate cardiac hypertrophy independently and induce different patterns of gene expression.

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Section: Discussionmentioning

confidence: 99%

Effects of gradual coronary artery occlusion and exercise training on gene expression in swine heart

et al. 2006

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Section: Discussionmentioning

confidence: 99%

“…Reduced rates of Ca 2ϩ uptake by the sarcoplasmic reticular Ca 2ϩ pump [sarco(endo)plasmic reticulum Ca 2ϩ -ATPase (SERCA2)] during early diastole (4,12,30) and increased left ventricular stiffness, which may result from altered deposition of myocardial collagen (23,33), are likely mechanisms for the reduction in early diastolic filling that accompanies aging. In senescent rats, training increases sarcoplasmic reticular Ca 2ϩ uptake (32), attenuates the age-associated changes in collagen deposition (33), and attenuates diastolic dysfunction (2). Whereas SERCA2a content is reduced in aged human myocardium (4), the effect of endurance training on SERCA2 content or rates of Ca 2ϩ sequestration have not been examined in humans, and studies using noninvasive methods, such as Doppler echocardiography to measure a training effect on diastolic function in older men are equivocal (2,8,10).…”

Section: Discussionmentioning

confidence: 99%

Left ventricular diastolic filling and systolic function of young and older trained and untrained men

Baldi¹,

McFarlane²,

Oxenham³

et al. 2003

Journal of Applied Physiology

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Left ventricular diastolic filling and systolic function of young and older trained and untrained men. J Appl Physiol 95: 2570-2575. First published July 25, 2003 10.1152/japplphysiol.00441.2003.-Aging is associated with impaired early diastolic filling; however, the effect of endurance training on resting diastolic function in older subjects is unclear. Heart rate and ventricular loading conditions affect mitral inflow velocities measured by Doppler echocardiography; therefore, tissue Doppler imaging of mitral annular velocity, which is relatively preload independent, was combined with mitral inflow velocity and maximal oxygen consumption (V O2 max) in young (20-35 yr) and older (60-80 yr) trained and untrained men to determine whether endurance training is associated with an attenuation of age-associated changes in diastolic filling. As expected, V O2 max was higher in trained men (P Ͻ 0.01) and lower in older men (P Ͻ 0.01). Peak early mitral inflow velocity (E) and early-to-late mitral inflow velocity ratios were lower in older vs. young men (P Ͻ 0.01); however, there was no training effect (P Ͼ 0.05). Peak early mitral annular velocity (EЈ) was higher and peak late mitral annular velocity (AЈ) was lower in young vs. older men (P Ͻ 0.01). A significant interaction effect was found for AЈ, EЈ/AЈ, and peak systolic mitral annular velocity (SЈ). Training was associated with lower AЈ in young and higher AЈ in older men. SЈ was greater in trained vs. untrained older men (P Ͻ 0.05), but it was similar in trained and untrained young men. These findings suggest that early diastolic filling is not affected by training in older men, and the effect of training on AЈ and SЈ is different in young and older men. diastolic function; aging; endurance training; maximal aerobic capacity (maximal oxygen consumption), tissue Doppler imaging AGING IS ASSOCIATED WITH AN increase in left ventricular stiffness (7), which results in a prolongation of isovolumic relaxation time (9) and incomplete relaxation of the ventricle during early diastolic filling (25). Numerous investigations have shown that peak early diastolic mitral inflow velocity (E) is reduced in aged individuals (2,10,17,18,34). To maintain ventricular filling and stroke volume, peak late diastolic filling velocity (A) increases with age (2, 17), resulting in an age-associated decline in the early-to-late mitral inflow velocity ratio (E/A) ratio (17).Aerobic fitness is associated with improved early diastolic function in young healthy subjects. Young trained athletes have increased E (20) and E/A (8, 11, 22, 26) compared with their nontrained counterparts. However, evidence to suggest that training has a similar effect in older athletes, or that training attenuates the normal age-associated decrease in E/A is inconclusive (8,10,28,31). Endurance training has been shown to improve peak filling rate in older healthy men (19), and the E/A has been shown to be higher in highly trained older endurance athletes compared with agematched healthy controls (8). However, Fleg et...

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“…22,24 Connective tissue content and collagen cross-linking also decreased with endurance training. 25,26 Furthermore, exercise appears to have an antiapoptotic effect on myocytes that likely enhances chamber distensibility because myocytes are less stiff than collagen. 26,27 Thus, it is possible that lifelong endurance training may maintain myocyte volume and cell size and limit the development of fibrosis, thus preserving cardiac compliance.…”

Section: Physiologic Differences Between Ventricular Compliance and Rmentioning

confidence: 99%

“…25,26 Furthermore, exercise appears to have an antiapoptotic effect on myocytes that likely enhances chamber distensibility because myocytes are less stiff than collagen. 26,27 Thus, it is possible that lifelong endurance training may maintain myocyte volume and cell size and limit the development of fibrosis, thus preserving cardiac compliance.In contrast, myocardial relaxation is predominantly influenced by myocyte calcium handling, but appears to be species specific. For example, endurance training enhances calcium uptake and improves myocyte excitation-contraction coupling in rats, but not in canines.…”

mentioning

confidence: 99%

The Effects of Aging and Physical Activity on Doppler Measures of Diastolic Function

Prasad

Popović

Arbab‐Zadeh

et al. 2007

The American Journal of Cardiology

150

157

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Healthy aging results in changes in Doppler measures of diastolic function. It is unclear whether these alterations are a specific manifestation of the aging process or reflect a cardiac adaptation to a more sedentary lifestyle. It was hypothesized that healthy, but sedentary, aging would result in slowing of diastolic filling and myocardial relaxation, whereas lifelong endurance training would prevent such changes. Doppler data were measured in young subjects and sedentary and fit seniors across a broad range of loading conditions. Thirteen sedentary healthy (70 ± 4 years) and 12 fit Masters athlete (68 ± 3 years) seniors were recruited. Twelve young healthy (32 ± 9 years) subjects were used for comparison. Pulmonary capillary wedge pressure and Doppler variables were measured at the 6 loading conditions of baseline (twice), -15 and -30 mm Hg lower body negative pressure, and 2 levels of saline solution infusion. Doppler variables consisted of early and late mitral inflow velocity (E/A) ratio, isovolumetric relaxation time (IVRT), tissue Doppler velocities (TDI E mean ), and propagation velocity of mitral inflow. Aging resulted in a decrease in E/A ratio (p <0.001), TDI E mean (p <0.001), and propagation velocity of mitral inflow (p <0.001) and an increase in IVRT (p = 0.001). Lifelong endurance training did not completely prevent the changes in E/A ratio (p = 0.212), IVRT (p = 0.546), or propagation velocity of mitral inflow (p = 1.00). Fit seniors were able to achieve E/A ratios of 1.0 during baseline and saline solution infusion. TDI E mean was higher in fit versus sedentary seniors at baseline (p = 0.012) and during maximal lower body negative pressure (p = 0.036), but not during saline solution infusion (p = 0.493). In conclusion, age-associated abnormalities in Doppler measures of myocardial filling and relaxation are only partially minimized by lifelong endurance training and therefore may be more specific to the aging process than secondary to years of deconditioning.Normal aging, even in the absence of co-morbidities, results in marked changes in Doppler measures of ventricular filling and relaxation, including reversal of the early and late mitral inflow velocities (decreased E/A ratio) and prolongation of isovolumetric relaxation time (IVRT). 1 These variables, although reproducible, have several limitations in their ability to accurately reflect diastolic function, including significant preload dependence and lack of specificity for dynamic relaxation processes. 2 In addition, it is unclear whether alterations in these Doppler variables with senescence are a specific manifestation of the aging process or reflect a secondary cardiac adaptation to a more sedentary lifestyle. Recently, our laboratory showed that static left ventricular stiffness markedly increased during healthy sedentary aging, whereas lifelong endurance training preserved static left ventricular compliance. 4 These data showed that ≥1 component of diastole, namely static chamber compliance, was significantly influenced by fit...

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Exercise training attenuates aging-associated increases in collagen and collagen crosslinking of the left but not the right ventricle in the rat

Cited by 62 publications

References 33 publications

Effects of gradual coronary artery occlusion and exercise training on gene expression in swine heart

Effects of gradual coronary artery occlusion and exercise training on gene expression in swine heart

Left ventricular diastolic filling and systolic function of young and older trained and untrained men

The Effects of Aging and Physical Activity on Doppler Measures of Diastolic Function

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