Search results for "Muscles"
showing 10 items of 616 documents
Activity of acid hydrolases in skeletal muscle of untrained, trained and detrained mice of different ages.
1978
The activities of p-nitrophenylphosphatase, beta-glucuronidase and beta-N-acetylglucosaminidase from crude skeletal muscle homogenates of 4 and 7 months old mice were assayed after short-term intensive and long-term moderate training and after terminated training. In the older untrained mice the activity of the hydrolases was higher than in the younger mice. The level increased with training and this increase was far more pronounced in the older animals. Cessation of training for 7 and 21 days decreased this activity in the older animals but it was again increased 42 days later and close to the level observed in the trained mice. In young mice 3 days' terminated training increased the activ…
Type IV collagen and laminin in slow and fast skeletal muscle in rats--effects of age and life-time endurance training.
1988
The changes in the biochemical composition of basement membrane (BM) in slow-twitch (m. soleus, MS) and fast-twitch (m. rectus femoris, MRF) skeletal muscles of rats were studied during aging and life-time endurance training (treadmill running). The concentrations of the 7S domain of type IV collagen and of the P2 fragment of laminin were determined with radioimmunoassays in the muscles of rats aged 1, 2, 4, 10, and 24 months. The concentration of type IV collagen was higher in MS than in MRF and increased significantly with age. At older ages, the concentration tended to be higher in the MS of trained than untrained rats. The concentration of laminin was significantly higher in MRF than in…
The biology of the metabolic syndrome and aging.
2015
Aging of the world population is a major contributor to the growing prevalence of the metabolic syndrome, as older persons are frequently affected by the constellation of cardiovascular and metabolic risk factors that constitute the syndrome. The metabolic syndrome has been related to the increasing prevalence of obesity, which is escalating even among older age groups. The present review covers data on the novel proposed biological mediators of the metabolic syndrome, which are as well linked to the aging process.Relevant biological mediators of metabolic syndrome and unhealthy aging include sarcopenic obesity, insulin resistance with ectopic fat accumulation, magnesium metabolism alterati…
Glucose 6-P dehydrogenase delays the onset of frailty by protecting against muscle damage.
2021
Background: Frailty is a major age-associated syndrome leading to disability. Oxidative damage plays a significant role in the promotion of frailty. The cellular antioxidant system relies on reduced nicotinamide adenine dinucleotide phosphate (NADPH) that is highly dependent on glucose 6-P dehydrogenase (G6PD). The G6PD-overexpressing mouse (G6PD-Tg) is protected against metabolic stresses. Our aim was to examine whether this protection delays frailty. Methods: Old wild-type (WT) and G6PD-Tg mice were evaluated longitudinally in terms of frailty. Indirect calorimetry, transcriptomic profile, and different skeletal muscle quality markers and muscle regenerative capacity were also investigate…
Failure of opioids to affect excitation and contraction in isolated ventricular heart muscle
1989
The opioid agonists morphine (selective for mu-receptors) and ethylketocyclazocine (selective for kappa-receptors), at concentrations evoking strong effects in neuronal structures, did not significantly affect the configuration of the intracellularly recorded action potential and the force of contraction in ventricular heart muscle isolated from guinea pigs, rabbits and man. These results suggest that any changes of heart functions in vivo in response to opioid-like drugs are probably not mediated postsynaptically at the myocardial cell membrane but rather presynaptically, influencing the release of noradrenaline and/or acetylcholine from the nerve terminals.
Increased Joint Mobility Is Associated With Impaired Transversus Abdominis Contraction.
2020
Mitchell, UH, Owen, PJ, Rantalainen, T, and Belavý, DL. Increased joint mobility is associated with impaired transversus abdominis contraction. J Strength Cond Res 36(9): 2472-2478, 2022-Increased joint mobility is a risk factor for joint injury, but muscle function may be able to compensate for it. Current evidence suggests reduced force production capacity in people with hypermobility. However, little is known about the lumbar spine. The purpose of this cross-sectional study was to assess whether there was a link between joint mobility and transverse abdominis and multifidus muscles contraction, muscles ascribed a core-stability role. Using a modified quantitative version of the Beighton …
Core Muscle Activity, Exercise Preference, and Perceived Exertion during Core Exercise with Elastic Resistance versus Machine
2015
Objectives. To investigate core muscle activity, exercise preferences, and perceived exertion during two selected core exercises performed with elastic resistance versus a conventional training machine.Methods. 17 untrained men aged 26–67 years participated in surface electromyography (EMG) measurements of five core muscles during torso-twists performed from left to right with elastic resistance and in the machine, respectively. The order of the exercises was randomized and each exercise consisted of 3 repetitions performed at a 10 RM load. EMG amplitude was normalized (nEMG) to maximum voluntary isometric contraction (MVC).Results. A higher right erector spinae activity in the elastic exer…
Muscle adenylate kinase in Duchenne muscular dystrophy
1986
Abstract On the basis of electrophoretic and enzyme inhibition studies it was postulated that an aberrant adenylate kinase occurs in muscle and serum of patients with Duchenne muscular dystrophy (Schirmer, R.H. and Thuma, E. (1972) Biochim. Biophys. Acta 268, 92–97; Hamada, M. et al. (1981) Biochim. Biophys. Acta 660, 227–237; Hamada et al. (1985) J. Biol. Chem. 260, 11595–11602. On the basis of the following results we conclude that Duchenne muscular dystrophy patients do not possess an unusual adenylate kinase isoenzyme. (1) In muscle biopsies from five Duchenne patients, the electrophoretic mobility of adenylate kinase and the inhibition of the enzyme by P 1 , P 5 -di(adenosine-5′)pentap…
Postural Sensorimotor Control on Anorectal Pressures and Pelvic Floor Muscle Tone and Strength: Effects of a Single 5P® LOGSURF Session. A Cross-Sect…
2021
Pelvic floor dysfunction (PFD) is a functional condition present most frequently in women. Despite pelvic floor muscle training being considered by the International Continence Society (ICS) as the first-line treatment in uncomplicated urinary incontinence, other more comprehensive postural methods as 5P® LOGSURF have emerged. This preliminary cross-sectional study explores the effects of a single 5P® LOGSURF session on pelvic floor muscle (PFM) tone and strength (MVC), resting anal tone, intrarectal pressure, and deep abdominal muscles activation. Thirty women were included (11 without PFD and 19 with PFD). Primary outcome measures were PFM tone, PFM MVC and resting anal tone and secondary…
Avoidant coping, verbal-autonomic response dissociation and pain tolerance
2006
Higher autonomic reactivity relative to self-reported discomfort, often found in repressors and avoidant copers might be associated with a diminished perception of bodily symptoms. This study aimed at relating such so-called verbal-autonomic response dissociation to pain tolerance. Eighty-five volunteers underwent a public speaking task and a cold pressor test. Heart rate and negative affect in response to the speech, and pain ratings and facial muscle responses for the cold pressor were obtained. A dissociation score was calculated for each individual in response to speech, thereby subtracting standardized changes in negative affect from standardized changes in heart rate. Response dissoci…