Search results for " Muscle"
showing 10 items of 1495 documents
Increased physical activity decreases hepatic free fatty acid uptake: a study in human monozygotic twins
2006
Exercise is considered to be beneficial for free fatty acid (FFA) metabolism, although reports of the effects of increased physical activity on FFA uptake and oxidation in different tissues in vivo in humans have been inconsistent. To investigate the heredity-independent effects of physical activity and fitness on FFA uptake in skeletal muscle, the myocardium, and liver we used positron emission tomography (PET) in nine healthy young male monozygotic twin pairs discordant for physical activity and fitness. The cotwins with higher physical activity constituting the more active group had a similar body mass index but less body fat and 18 +/- 10% higher (P < 0.001) compared to the less active …
Effects of fatiguing jumping exercise on mRNA expression of titin-complex proteins and calpains.
2009
Eccentric exercise induced by electrostimulation increases mRNA expression of titin-complex proteins in rodent skeletal muscle. In this study, mRNA expression of titin, muscle LIM protein (MLP), cardiac ankyrin repeat protein (CARP), ankyrin repeat domain protein 2 (Ankrd2), diabetes-related ankyrin repeat protein (DARP), and calcium-activated proteinases, calpains, were investigated in human skeletal muscle after fatiguing jumping exercise. Fatiguing jumping exercise did not change mRNA expression of titin, DARP, calpain 1, or calpain 3. MLP, Ankrd2 and calpain 2 mRNA levels were increased 2 days postexercise. CARP mRNA level was already elevated 30 min and remained elevated 2 days postexe…
Evidence that ATP or a related purine is an excitatory neurotransmitter in the longitudinal muscle of mouse distal colon
2007
BACKGROUND AND PURPOSE: This study analysed the contribution of the purinergic system to enteric neurotransmission in the longitudinal muscle of mouse distal colon. EXPERIMENTAL APPROACH: Motor responses to exogenous ATP and to nerve stimulation in vitro were assessed as changes in isometric tension. KEY RESULTS: ATP induced a concentration-dependent contraction, reduced by 4-[[4-formyl-5-hydroxy-6-methyl-3-[(phosphonooxy)methyl]-2-pyridinyl]azo]-1,3-benzene disulphonic acid (PPADS), suramin, P2Y purinoreceptor desensitisation with adenosine 5'-O-2-thiodiphosphate (ADPbetaS), and atropine, but unaffected by P2X purinoceptor desensitisation with alpha,beta-methylene ATP (alpha,beta-meATP) an…
Transcranial direct current stimulation preconditioning modulates the effect of high-frequency repetitive transcranial magnetic stimulation in the hu…
2012
Experimental studies emphasize the importance of homeostatic plasticity as a mean of stabilizing the properties of neural circuits. In the present work we combined two techniques able to produce short-term (5-Hz repetitive transcranial magnetic stimulation, rTMS) and long-term (transcranial direct current stimulation, tDCS) effects on corticospinal excitability to evaluate whether and how the effects of 5-Hz rTMS can be tuned by tDCS preconditioning. Twelve healthy subjects participated in the study. Brief trains of 5-Hz rTMS were applied to the primary motor cortex at an intensity of 120% of the resting motor threshold, with recording of the electromyograph traces evoked by each stimulus o…
Medial gastrocnemius muscle and tendon interaction during gait in typically developing children and children with cerebral palsy
2020
1. IntroductionEfficient gait is dependent on optimal interaction between musclesand tendons [1]. Pathological changes in the extensibility of the MGmuscle fascicles, whole muscle-belly and Achilles tendon have beenreported in children with spastic cerebral palsy (CP) [2]. Studying therelative length of these tissues during gait can improve our understandingof their dynamics and, inferably, the control strategies used inCP. In-vivo dynamic ultrasound imaging has been used to visualise theinteraction between the MG muscle and tendon during 3D gait analysis.However, most studies combined ultrasound imaging of one variable(either fascicles or muscle-belly and tendon) with some form ofmusculosk…
Function of the flexor hallucis longus muscle : what do we know? = A flexor hallucis longus izom működése : mit tudunk róla?
2016
Flexor hallucis longus (FHL) muscle has several functions, including plantarflexion of the ankle, flexion of the big toe and support of the medial longitudinal arch. To date, only a few studies have used non-invasive methods to examine FHL behavior during real-life movements, although the proper functioning of this muscle may be important to increase sport performance, the altered FHL function may contribute to the susceptibility to Achilles tendinopathy and the function of FHL is altered in other clinical conditions such as flatfoot. FHL seems to be multifunctional but other active and passive structures also contribute to the same functions. Because of the multifunctionality of the foot s…
Acute effects of cold pack on mechanical properties of the quadriceps muscle in healthy subjects.
2012
Purpose: To examine the effects of local cooling on mechanical properties of the quadriceps muscle in healthy subjects. Subjects: Thirty-nine healthy subjects (27 women, 12 men, mean age 39, range 20e62) volunteered. Methods: A cold gel pack was applied to the quadriceps muscle for 20 min. Properties were quantified by analyzing the frequency (tension), decrement (elasticity) and stiffness of damped oscillations and the compliance of the muscle before, immediately after and after 15-min after cooling. Results: The largest responses immediately after cooling were seen in the oscillation decrement parameter, 7.9 (3.7e12.1) %, and in the compliance parameter, � 7.5 (� 9.8 to � 5.3) %. Response…
Age affects myosin relaxation states in skeletal muscle fibers of female but not male mice
2018
The recent discovery that myosin has two distinct states in relaxed muscle–disordered relaxed (DRX) and super-relaxed (SRX)–provides another factor to consider in our fundamental understanding of the aging mechanism in skeletal muscle, since myosin is thought to be a potential contributor to dynapenia (age-associated loss of muscle strength independent of atrophy). The primary goal of this study was to determine the effects of age on DRX and SRX states and to examine their sex specificity. We have used quantitative fluorescence microscopy of the fluorescent nucleotide analog 2′/3′-O-(N-methylanthraniloyl) ATP (mantATP) to measure single-nucleotide turnover kinetics of myosin in skinned skel…
Control of adenine nucleotide metabolism and glycolysis in vertebrate skeletal muscle during exercise.
1996
The turnover of adenosine triphosphate (ATP) in vertebrate skeletal muscle can increase more than a hundredfold during high-intensity exercise, while the content of ATP in muscle may remain virtually unchanged. This requires that the rates of ATP hydrolysis and ATP synthesis are exactly balanced despite large fluctuations in reaction rates. ATP is regenerated initially at the expense of phosphocreatine (PCr) and then mainly through glycolysis from muscle glycogen. The increased ATP turnover in contracting muscle will cause an increase in the contents of adenosine diphosphate (ADP), adenosine monophosphate (AMP) and inorganic phosphate (P(i)), metabolites that are substrates and activators o…
Contribution of IL-17-producing {gamma}{delta} T cells to the efficacy of anticancer chemotherapy.
2011
IL-17 production by γδ T cells is required for tumor cell infiltration by IFN-γ–producing CD8+ T cells and inhibition of tumor growth in response to anthracyclines.