Search results for "Sarcolemma"
showing 6 items of 26 documents
Capillaries within human skeletal muscle fibers.
1991
Internalized capillaries, i.e. capillaries within muscle fibers, represent a rare myopathological feature. This was systematically studied in 923 muscle biopsy specimens and found in 24, chiefly in the gastrocnemius muscle, more rarely in the biceps and quadriceps muscles affecting males more often than females and most frequently associated with juvenile spinal muscular atrophy or Becker's muscular dystrophy. Internalized capillaries, often multiple, ran along the long axis of the muscle fiber within an "internalized" extracellular space and were almost exclusively seen in type I myofibers. Internalization seems to start at the site of fiber splitting while penetration through the intact s…
Lipid peroxidation capacities in the myocardium of endurance-trained rats and mice in vitro.
1992
The endurance-training programme in Experiment 1 (Exp. 1) consisted of a total swimming time of 149–159 h per male Han Wistar rat and in Experiment 2 (Exp. 2) the male NMRI-mice run on a treadmill at a speed of 25 m min-1 1 h per day, 5 days a week for 3 weeks. One group of the rat hearts was perfused with 0.3 mm cumene hydroperoxide (CumOOH) while the others were fractioned (mitochondria, sarcolemma and sarcoplasmic reticulum) and these cell fractions and homogenates were used to determine the total concentration of peroxidative lipids and the susceptibility to lipid peroxidation. The perfusion with CumOOH caused the release of thiobarbituric acid reactive substances (TBARS) into the perfu…
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…
Gastric emptying, small intestinal transit and fecal output in dystrophic (mdx) mice.
2009
Duchenne muscular dystrophy (DMD), which results from deficiency in dystrophin, a sarcolemma protein of skeletal, cardiac and smooth muscle, is characterized by progressive striated muscle degeneration, but various gastrointestinal clinical manifestations have been observed. The aim was to evaluate the possible impact of the dystrophin loss on the gastrointestinal propulsion in mdx mice (animal model for DMD). The gastric emptying of a carboxymethyl cellulose/phenol red dye non-nutrient meal was not significantly different at 20 min from gavaging between wild-type and mdx mice. The intestinal transit and the fecal output were significantly decreased in mdx versus normal animals, although th…
Immune-mediated rippling muscle disease with myasthenia gravis: a report of seven patients with long-term follow-up in two.
2009
We report seven patients with immune-mediated rippling muscle disease (iRMD) and AChR-antibody positive myasthenia gravis (MG) without germline caveolin-3 gene mutations. We describe the follow-up of two patients and the clinical features of five new patients (1 female, 4 male, aged 32 to 69 years). These presented with significant generalized, exercise-induced and electrically-silent muscle rippling with myalgia, combined with generalized MG. In two of the seven patients, MG appeared before iRMD. Mediastinal imaging excluded thymic alterations in all, although two had other coincident tumours. Myalgia and rippling were aggravated by acetylcholinesterase-inhibitor treatment. Generalized MG …