Abstract：
:Age-related declines in human skeletal muscle performance may be caused, in part, by decreased responsivity of muscle fibers to calcium (Ca2+). This study examined the contractile properties of single vastus lateralis muscle fibers with various myosin heavy chain (MHC) isoforms (I, I/IIA, IIA and IIAX) across a range of Ca2+ concentrations in 11 young (24.1±1.1years) and 10 older (68.8±0.8years) men and women. The normalized pCa-force curve shifted rightward with age, leading to decreased activation threshold (pCa10) and/or Ca2+ sensitivity (pCa50) for all MHC isoforms examined. In older adults, the slope of the pCa-force curve was unchanged in MHC I-containing fibers (I, I/IIA), but was steeper in MHC II-containing fibers (IIA, IIAX), indicating greater cooperativity compared to young adults. At sub-maximal [Ca2+], specific force was reduced in MHC I-containing fibers, but was minimally decreased in MHC IIA fibers as older adults produced greater specific forces at high [Ca2+] in these fibers. Lessor pCa50 in MHC I fibers independently predicted reduced isokinetic knee extensor power across a range of contractile velocities, suggesting that the Ca2+ response of slow-twitch fibers contributes to whole muscle dysfunction. Our findings show that aging attenuates Ca2+ responsiveness across fiber types and that these cellular alterations may lead to age-related reductions in whole muscle power output.
journal_name
Exp Gerontoljournal_title
Experimental gerontologyauthors
Straight CR,Ades PA,Toth MJ,Miller MSdoi
10.1016/j.exger.2017.12.007subject
Has Abstractpub_date
2018-02-01 00:00:00pages
84-92eissn
0531-5565issn
1873-6815pii
S0531-5565(17)30708-8journal_volume
102pub_type
杂志文章abstract：:Reductions in physical performance, cognitive impairment (CI) and decline (CD), are common in older age, but few prospective cohort studies have considered the relationship between these domains. In this study we investigated whether reduced physical performance and low handgrip/lower limbs strength, could predict a h...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2016.05.008
更新日期：2016-08-01 00:00:00
abstract：:The loss of bone mineral with aging and subsequent development of osteoporosis is a common problem in elderly women, and as life expectancy increases, in elderly men as well. Space flight also causes bone loss and could be a limiting factor for long duration missions, such as, a Mars expedition or extended occupation ...
journal_title：Experimental gerontology
pub_type： 杂志文章,评审
doi：10.1016/0531-5565(91)90011-a
更新日期：1991-01-01 00:00:00
abstract：:Aging is associated with a decline in muscle force that exceeds loss of muscle mass, suggesting that factors other than sarcopenia affect age-related muscle weakness. Here, we investigate in situ muscle force and sarcoplasmic reticulum (SR) properties in gastrocnemius muscles of adult (6-8 months) and aged (24 months)...
journal_title：Experimental gerontology
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doi：10.1016/j.exger.2013.11.018
更新日期：2014-02-01 00:00:00
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journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2015.06.003
更新日期：2015-09-01 00:00:00
abstract：:In young mice exposed to aerosol infection with Mycobacterium tuberculosis removal of the gammadelta T cell population by targeted gene disruption does not affect the expression of host resistance, but does influence the integrity of the early granulomatous response. The current study demonstrates that in aged gammade...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/s0531-5565(00)00199-6
更新日期：2001-02-01 00:00:00
abstract：:Motor performance of rats of different ages was determined in a cross sectional study. The design includes a test battery of seven motor tasks of graduated complexity. The results show a hierarchical order of impairments of motor functions in aging rats; that is, the more complex the task requirement, the earlier and ...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/0531-5565(83)90018-9
更新日期：1983-01-01 00:00:00
abstract：BACKGROUND:Hyaline articular cartilage, which protects the bones of diarthrodial joints from forces associated with load bearing, frictions, and impacts has very limited capacities for self-repair. Over the years, the trend of treatments has shifted to regenerations and researchers have been on the quest for a lasting ...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2018.01.020
更新日期：2018-04-01 00:00:00
abstract：:Male life history and resource allocation is not frequently studied in aging and life span research. Here, we verify that males of long-lived fruit-feeding butterfly species have reduced longevity on restricted diets [Beck, J., 2007. The importance of amino acids in the adult diet of male tropical rainforest butterfli...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2009.06.008
更新日期：2009-09-01 00:00:00
abstract：BACKGROUND AND PURPOSE:Stroke associated infection (within the first seven days) occurs in approximately half of stroke patients and is associated with a worse prognosis, especially in the elderly. It is uncertain what factors predict stroke associated infection, yet identification of a suitable biomarker for infection...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2013.07.003
更新日期：2013-09-01 00:00:00
abstract：BACKGROUND:Oxidative stress and inflammation may contribute to anabolic resistance in response to protein and exercise in older adults. We investigated whether consumption of montmorency cherry concentrate (MCC) increased anabolic sensitivity to protein ingestion and resistance exercise in healthy older men. METHODS:S...
journal_title：Experimental gerontology
pub_type： 杂志文章,随机对照试验
doi：10.1016/j.exger.2018.06.007
更新日期：2018-09-01 00:00:00
abstract：:Raw bioelectrical impedance analysis (BIA) data [resistance (R); reactance (Xc)] through bioelectrical impedance vector analysis (BIVA) and phase angle (PhA) have been used to evaluate cellular function and hydration status. The purpose of this investigation was to examine the effects of resistance training (RT) on cl...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2015.12.002
更新日期：2016-02-01 00:00:00
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journal_title：Experimental gerontology
pub_type： 杂志文章,评审
doi：10.1016/j.exger.2010.09.008
更新日期：2011-02-01 00:00:00
abstract：:Initial velocity of GABA uptake in hypothalamic synaptosomes has been measured in aged animals as a function of both sodium and GABA concentration and compared to previous studies in young animals. The data give good fit to the model found previously to give minimal best fit to control data. Thus it appears that aging...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/0531-5565(83)90005-0
更新日期：1983-01-01 00:00:00
abstract：OBJECTIVES:To evaluate lean mass index (LMI) measured by bioimpedance (BIA) and anthropometry compared to densitometry (DXA) in elderly outpatients from a tertiary care hospital. METHODS:Participants were over 60-year-old men, presenting no dementia or disability, from a tertiary geriatric ambulatory. LMI obtained by ...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2020.111020
更新日期：2020-09-01 00:00:00
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journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/0531-5565(92)90003-i
更新日期：1992-09-01 00:00:00
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journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/0531-5565(90)90061-6
更新日期：1990-01-01 00:00:00
abstract：:A micromethod was used to study myelin from individual rat optic nerves as a function of age. Protein and galactolipid content as well as 2',3'-cyclic nucleotide phosphohydrolase (CNPase) activity at ages 2, 4, 22, and 28 months were determined. Protein content increased significantly at 22 months and decreased at adv...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/0531-5565(89)90013-2
更新日期：1989-01-01 00:00:00
abstract：:In order to establish the role of calcitonin (CT) in postmenopausal bone loss, we studied CT metabolism in 25 pre- and postmenopausal women. Postmenopausal women presented a highly significant reduction of CT basal levels compared to premenopausal females (p less than 0.01). Also, production rates of CT in osteoporoti...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/0531-5565(90)90072-a
更新日期：1990-01-01 00:00:00
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journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2011.06.001
更新日期：2011-10-01 00:00:00
abstract：:Aging is the major risk factor for numerous brain diseases. This is especially true for Alzheimer's disease (AD), a peculiar neurodegenerative disorder in that it results from the synergy of two simultaneous but distinct degenerating processes: A beta and tau pathologies. For AD, and for most neurodegenerative disorde...
journal_title：Experimental gerontology
pub_type： 杂志文章,评审
doi：10.1016/j.exger.2003.09.010
更新日期：2003-11-01 00:00:00
abstract：:Threat-related changes in postural control and their associations with changes in emotional and cognitive states are influenced by postural threat experience, however, limited work has explored individuals' capacity to adapt threat-related responses over longer periods of threat exposure. This study examined the effec...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2019.04.015
更新日期：2019-07-15 00:00:00
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journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/0531-5565(89)90014-4
更新日期：1989-01-01 00:00:00
abstract：INTRODUCTION:Right ventricular dysfunction (RVD), submassive pulmonary embolism (PE), elevated systolic pulmonary artery pressure (sPAP), elevated cardiac troponin I (cTnI) and old age are well-known risk factors for poor outcome in acute normotensive PE. The aim of this analysis was to calculate age cut-off values to ...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2015.05.007
更新日期：2015-09-01 00:00:00
abstract：:Neural correlates of placebo analgesia (PA) in patients with neurocognitive disorders have not yet been elucidated. The present study aimed to evaluate how and to what extent executive (dys)functions of the medial prefrontal cortex (MPFC) may be related to PA. To this end, twenty-three subjects complaining of differen...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2019.01.011
更新日期：2019-04-01 00:00:00
abstract：:Atrophy of the thymus, the primary site of T lymphocyte generation, is a hallmark of the aging immune system. Age-associated thymic atrophy results in diminished output of new, naïve T cells, with immune sequelae that include diminished responses to novel pathogenic challenge and vaccines, as well as diminished tumor ...
journal_title：Experimental gerontology
pub_type： 杂志文章,评审
doi：10.1016/j.exger.2017.12.022
更新日期：2018-05-01 00:00:00
abstract：:The adult blowfly, Phormia regina, reveals a substantial homeostatic capability when examined for its ability to regulate externally administered additions to its blood sugar. As well, results of experiments done at intervals throughout the entire adult life of the fly show that there is no decrease over time in the e...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/0531-5565(86)90058-6
更新日期：1986-01-01 00:00:00
abstract：:The purpose of this study was to examine the effect of a mentally fatiguing task on postural responses to unexpected backward perturbations in sixteen young and sixteen older women. Postural responses were characterized by center of pressure (COP) displacement, corrective COP peak velocity, and electromyography (EMG) ...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2020.110840
更新日期：2020-04-01 00:00:00
abstract：:Accumulation of myeloid-derived suppressor cells (MDSCs) in aged hosts contribute to the age-related increase of susceptibility to murine breast adenocarcinoma and co-stimulatory molecules expressed in MDSCs are essential for MDSCs-mediated immune suppression. However, the co-stimulatory molecules that exert a direct ...
journal_title：Experimental gerontology
pub_type： 杂志文章
doi：10.1016/j.exger.2014.12.001
更新日期：2015-01-01 00:00:00
abstract：:Stem cells are located throughout the adult body of higher organisms, supporting a continuous renewal and repair of tissues. Unique abilities of stem cells are self-renewal and multipotential differentiation. It is, therefore, of critical importance for an organism to maintain and control quantity and quality of stem ...
journal_title：Experimental gerontology
pub_type： 杂志文章,评审
doi：10.1016/j.exger.2005.07.006
更新日期：2005-12-01 00:00:00
abstract：:Accumulating evidence from diverse experiments, including heterochronic parabiosis-the surgical joining of two animals of different ages-has highlighted the importance of systemic factors in the progressive functional decline of various organs and tissues during aging. The major metabolic pathway of tryptophan, an ess...
journal_title：Experimental gerontology
pub_type： 杂志文章,评审
doi：10.1016/j.exger.2019.110793
更新日期：2020-02-01 00:00:00
