Search results for " Muscle"

Effects of sodium fluoride on the mechanical activity in mouse gastric preparations.

2005

The aim of the present study was to investigate the responses induced by sodium fluoride (NaF) on gastric mechanical activity, using mouse whole-stomach preparations. The mechanical activity was recorded in vitro as changes of intraluminal pressure. In most of the preparations, NaF induced a tetrodotoxin-insensitive biphasic effect characterized by early relaxation followed by slowly developing contractile response. The contraction was dependent on the concentration of NaF, whereas the relaxation was observed at only 10–30 mmol/L NaF. The contractile effect was significantly reduced by nifedipine (an L-type Ca2+channel blocker), ryanodine or ruthenium red (inhibitors of Ca2+release from sar…

Molecular adaptations of voltage-gated sodium ion channel related proteins after fatiguing stretch-shortening cycle exercise

2008

Dystrophin associated protein alpha-syntrophin is known to interact with voltage-gated sodium ion channel (NaCh). Dystrophin is known to be sensitive to eccentric muscle actions. For this reason, the function of the NaChs might also be affected. Molecular adaptations of dystrophin, alpha-syntrophin and NaChs were investigated after fatiguing stretch-shortening cycle (SSC) exercise, which consisted of unilateral jumps on a sledge apparatus. Muscle biopsies were taken from the vastus lateralis muscle of eight healthy subjects immediately after (IA) and 2 days after (2D) the exercise to analyze mRNA levels and immunohistochemical staining patterns. SSC exercise resulted in decreased isometric …

Gender differences in skeletal muscle fibre damage after eccentrically biased downhill running in rats

1999

Specific antibodies against structural proteins of muscle fibres (actin, desmin, dystrophin) and extracellular matrix (fibronectin) were used to study the effect of eccentrically biased downhill running exercise (13,5 degrees, 17 m min(-1), 130 min) on the magnitude and properties of myofibre injury in the quadriceps femoris muscle of male and female rats. Muscle beta-glucuronidase activity, a quantitative indicator of muscle damage, showed clearly smaller increase in female than in male rats during the 4-day period following exercise. A similar course of histopathological changes was observed in both sexes, although females showed slower and less marked changes than males. In males, discon…

Effects of Resistance Training of Peripheral Muscles Versus Respiratory Muscles in Older Adults With Sarcopenia Who are Institutionalized: A Randomiz…

2018

[EN] This study compares the effects of two resistance training programs in peripheral and respiratory musculature on muscle mass and strength and physical performance and identifies the appropriate muscle mass parameter for assessing the intervention effects. Thirty-seven institutionalized older Spanish adults with sarcopenia were analyzed: control group (n = 17), respiratory muscle training group (n = 9), and peripheral muscle training group (n = 11). Measured outcomes were appendicular skeletal muscle mass (ASM/height(2), ASM/weight, and ASM/BMI), isometric knee extension, arm flexion and handgrip strength, maximal inspiratory and expiratory pressures, and gait speed pre- and postinterve…

Can Vitamin D deficiency influence muscle perfomance in post-menopausal women? A multicenter retrospective study

2018

Background: The presence of the vitamin D receptor (VDR) has been recently demonstrated in human muscle supporting the theory of a role of vitamin D in the proliferation and differentiation of muscle cells. So far only few studies investigated the association between vitamin D and muscle performance in postmenopausal women. Aim: To define the functional impact of vitamin D deficiency. Design: Multicenter retrospective study. Setting: Five Italian outpatient services of Physical and Rehabilitation Medicine (PRM). Population: Postmenopausal women. Methods: We divided the population in two groups based on the threshold of 30 ng/mL as cut-off to define sufficient and insufficient serum levels o…

Gelatinases and physical exercise: A systematic review of evidence from human studies

2017

Background Matrix metalloproteinases (MMPs), particularly gelatinase A (MMP-2) and gelatinase B (MMP-9), as well as their tissue inhibitors (TIMP-1 and TIMP-2), are involved in the development of skeletal muscle tissue, in the repair process after muscle injury and in the adaptive modifications induced by physical exercise in skeletal muscle. This paper aims at reviewing results from human studies that investigated the role of gelatinases and their inhibitors in skeletal muscle response to acute physical exercise or training. Methods Electronic databases PubMed/MEDLINE, Scopus and Web of Science were searched for papers published between January 2000 and February 2017. The papers were eligi…

2021

Sports-related pain and injury is directly linked to tissue inflammation, thus involving the autonomic nervous system (ANS). In the present experimental study, we disable the sympathetic part of the ANS by applying a stellate ganglion block (SGB) in an experimental model of delayed onset muscle soreness (DOMS) of the biceps muscle. We included 45 healthy participants (female 11, male 34, age 24.16 ± 6.67 years [range 18–53], BMI 23.22 ± 2.09 kg/m2) who were equally randomized to receive either (i) an SGB prior to exercise-induced DOMS (preventive), (ii) sham intervention in addition to DOMS (control/sham), or (iii) SGB after the induction of DOMS (rehabilitative). The aim of the study was t…

Neurochemistry of identified motoneurons of the tensor tympani muscle in rat middle ear

2008

The objective of the present study was to identify efferent and afferent transmitters of motoneurons of the tensor tympani muscle (MoTTM) to gain more insight into the neuronal regulation of the muscle. To identify MoTTM, we injected the fluorescent neuronal tracer Fluoro-Gold (FG) into the muscle after preparation of the middle ear in adult rats. Upon terminal uptake and retrograde neuronal transport, we observed FG in neurons located lateral and ventrolateral to the motor trigeminal nucleus ipsilateral to the injection site. Immunohistochemical studies of these motoneurons showed that apparently all contained choline acetyltransferase, demonstrating their motoneuronal character. Different…

Reduced Neck Muscle Strength and Altered Muscle Mechanical Properties in Cervical Dystonia Following Botulinum Neurotoxin Injections : A Prospective …

2016

Cervical dystonia (CD) is a focal dystonia causing involuntary activation of neck and shoulder muscles resulting in abnormal, sustained and painful posturing that may lead to physical disability and social withdrawal [1]. In recent years, botulinum neurotoxin (BoNT) has become the first line therapy for CD [2]. A subjective feeling of neck weakness has been reported as one of the most common localized adverse events of BoNT [2-7]. In clinical practice, this may sometimes be reported as having difficulty keeping the head upright. Although the effects of BoNT have been widely studied [2,5], there have been no prospective studies quantifying changes in maximal isometric neck muscle strength. O…

Effects of combined endurance and strength training on muscle strength, power and hypertrophy in 40-67-year-old men

2009

Both strength and endurance training have several positive effects on aging muscle and physical performance of middle-aged and older adults, but their combination may compromise optimal adaptation. This study examined the possible interference of combined strength and endurance training on neuromuscular performance and skeletal muscle hypertrophy in previously untrained 40-67-year-old men. Maximal strength and muscle activation in the upper and lower extremities, maximal concentric power, aerobic capacity and muscle fiber size and distribution in the vastus lateralis muscle were measured before and after a 21-week training period. Ninety-six men [mean age 56 (SD 7) years] completed high-int…