Age-Related Differences in the Force Generation Capabilities and Tendon Extensibilities of Knee Extensors and Plantar Flexors in Men

Abstract

Betaine is an important human nutrient obtained from various foods. In the present study, we assessed the anti-inflammatory effect of betaine on nuclear factor-jB (NF-jB) during aging. Sprague-Dawley (SD) rats, ages 7 and 21 months, were used in this study. The older rats were fed betaine. To elucidate the effect of betaine on oxidative stress-induced NF-jB and its signaling pathway at molecular levels, YPEN-1 cells were used. Results showed that betaine suppressed NF-jB and its related gene expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), vascular cell adhesion molecule-1 (VCAM-1), and intracellular cell adhesion molecule-1 (ICAM-1) in aged kidney. Furthermore, betaine attenuated oxidative stress-induced NF-jB via nuclear factor-inducing kinase/IjB kinase (NIK/IKK) and mitogen-activated protein kinases (MAPKs) in the YPEN-1 cells. On the basis of these results, we concluded that betaine suppressed the age-related NF-jB activities associated with upregulated NIK/IKK and MAPKs that were induced by oxidative stress. Thus, betaine might be useful as a preventive agent against the activation of NF-jB induced during inflammation and aging.

Falls, Muscle Strength, and Functional Abilities in Community-Dwelling Elderly Women

“…Being aware of the increasing reduction in strength that follows aging (1,2,4,5,14), the regular practice of physical activities, including resistance and balance exercises, contributes to the increase in strength of the lower limbs in elderly people who are more than 75 years of age (11). In the study by Scott et al, handled similarly to the present study, the authors found a reduction of 10% in relative risk of falling for each additional kilogram of knee extensor strength (14).…”

“…Elderly people have 20% to 48% loss of isometric strength of plantar flexors (2,5). Integrity of this muscle group and time of reaction present one strong correlation with the good performance of functional tasks that involve the sensorimotor system (6).…”

Life-long endurance running is associated with reduced glycation and mechanical stress in connective tissue

“…Stiffness of both animal and human tendons have been reported to increase (Shadwick 1990;Kubo et al 2007a), decrease (Stenroth et al 2012), or remain unchanged (Couppe et al 2009) with aging. Vidiik et al (Viidik et al 1996) showed that life-long endurance training may have counteracting systemic effects on the aging process as reflected by less stiff tail tendon tissue.…”

“…In line with this, we recently demonstrated that both enzymatic hydroxylysyl pyridinoline (HP) and lysyl pyridinoline (LP) cross-links and pentosidine, which is a marker of AGE, were more abundant in the patellar tendon of old men compared with that of young men (Couppe et al 2009). It is believed that greater AGE cross-link density increases tendon stiffness (Reddy et al 2002;Galeski et al 1977;Andreassen et al 1988;Bai et al 1992), however, mechanical properties of both animal and human tendon has been reported both to increase (Nielsen et al 1998;Shadwick 1990;Kubo et al 2007a;Wood et al 2011), decrease (Stenroth et al 2012; Karamanidis and Arampatzis 2006;Dressler et al 2002;Onambele et al 2006;Mian et al 2007) or remain unaltered with aging (Couppe et al 2009;Haut et al 1992;Hubbard and SoutasLittle 1984;Johnson et al 1994;Carroll et al 2008). Thus, to what extent aging influence mechanical properties of tendon tissue remains largely unknown.…”

Reliability and validity of trunk accelerometry-derived performance measurements in a standardized heel-rise test in elderly subjects

“…This has been shown with manual muscle testing [9], force measurements during isometric PF muscle contractions [28], and ankle power measurements during walking [29]. For this reason, the ability to quantify the kinetic aspects of the HR movement (force, power, etc.)…”