Search results for "Muscle Denervation"
showing 9 items of 19 documents
Uptake and metabolism of [3H]choline by the rat phrenic nerve-hemidiaphragm preparation
1987
A whole nerve-muscle preparation (about 160 mg) or an end-plate preparation (about 25 mg) of the rat phrenic nerve-hemidiaphragm were incubated with [3H]choline, to investigate choline uptake and choline metabolism. Choline uptake was measured from the disappearance of choline from the incubation medium during the loading period and from the retention of tritium in the tissue after the loading and washout period. Based on the results obtained with both methods the end-plate preparation takes up three times as much choline than the whole nerve-muscle preparation or a small muscle strip that was cut outside the end-plate region and had a similar size as the end-plate preparation. Choline upta…
Peripheral benzodiazepine binding sites on striated muscles of the rat: Properties and effect of denervation
1985
In order to test the hypothesis that peripheral benzodiazepine binding sites mediate some direct effects of benzodiazepines on striated muscles, the properties of specific 3H-Ro 5-4864 binding to rat biceps and rat diaphragm homogenates were investigated. In both tissues a single population of sites was found with a KD value of 3 nmol/l. The density of these sites in both muscles was higher than the density in rat brain, but was considerably lower than in rat kidney. Competition experiments indicate a substrate specificity of specific 3H-Ro 5-4864 binding similar to the properties already demonstrated for the specific binding of this ligand to peripheral benzodiazepine binding sites in many…
Formation and release of acetylpyrrolidinecholine (N-methyl, N-acetoxyethylpyrrolidinium) as a false cholinergic transmitter in the myenteric plexus …
1977
1. Longitudinal muscle strips of the guineapig small intestine were incubated with Tyrode solution containing the choline analogue pyrrolidinecholine. At the end of the incubation the concentrations of acetylcholine and its analogue acetylpyrrolidinecholine were determined in the strips by gas chromatography. 2. After 120 min of incubation with 1 mM pyrrolidinecholine, acetylpyrrolidinecholine comprised about 15% of the total amount of acetylcholine plus acetylpyrrolidinecholine. Electrical stimulation (1 Hz) of the strips during the incubation slightly increased the proportion of acetylpyrrolidinecholine to 21%. 3. The acetylcholine content of control strips increased significantly during …
Changes of energy metabolism, myosin light chain composition, lactate dehydrogenase isozyme pattern and fibre type distribution of denervated fast-tw…
1985
The influence of low frequency (8-10 Hz) electrical stimulation on denervated fast-twitch muscle from rabbit was investigated. Prolonged direct stimulation of denervated muscle resulted in higher oxidative enzyme activities. Furthermore, single fibre analyses for succinate dehydrogenase showed a more uniform distribution of activity in stimulated-denervated muscle when compared to normal muscle. As was also the case following stimulation of innervated muscle, glycolytic enzymes were decreased in activity and the LDH-isozyme pattern was also shifted towards heart type. No change of the myosin light chain pattern could be observed after 56 days of stimulation.
The fine structure of de-and reinnervated muscle spindles
1974
Reinnervated muscle spindles in lower lumbrical muscles of rats studied 17 days to 24 months after crushing the sciatic nerve showed a series of alterations which have not been analysed, thus far, by electron microscopy. There was a striking increase of the number of intrafusal muscle fibers seen in approximately 20% of reinnervated spindles. These spindles showed 5–11 intrafusal muscle fibers whereas normal spindles usually contained 3–4 fibers only.
Desmin pathology in neuromuscular diseases
1993
Desmin is an intermediate filament protein that in striated muscle is normally located at Z-bands, beneath the sarcolemma, and prominently at neuromuscular junctions. It is abundant during myogenesis and in regenerating fibers, but decreases in amount with maturation; in regenerating and denervated muscle fibers it is co-expressed with vimentin. Aggregates of desmin occur as nonspecific cytoplasmic bodies or cytoplasmic spheroid complexes, similar to the aggregates of keratin filaments in Mallory bodies or the neurofilament aggregates in Lewy bodies. In all three instances, alpha-B crystallin may be associated with desmin. There are now increasing numbers of neuromuscular disorders in which…
Expression of functional α7 nicotinic acetylcholine receptor during mammalian muscle development and denervation
1999
We have studied, on the transcriptional, protein and functional level, the expression of alpha7 nicotinic acetylcholine receptors (nAChR) in the course of rat muscle development, denervation and renervation. At foetal day 13, alpha7 nAChR expression was observed in somites and developing muscles of the back, but not yet in migrating myoblasts. Two days later, concomitant with myoblast aggregation, the alpha7 isoform began to be expressed in isolated myoblasts, with the highest level of expression in the frontal zone of the migrating wave. On foetal day 18, a time when the myoblasts in the upper hindleg have fused, alpha7 nAChR expression was most prominent in the outer layer of muscle tissu…
Expression of different isoforms of nitric oxide synthase in experimentally denervated and reinnervated skeletal muscle.
1997
Denervated muscle fibers express enhanced levels of stress and apoptosis-associated proteins and undergo apoptosis. In experimentally denervated and reinnervated rat facial muscle, we now evaluate changes in the expression patterns of different isoforms of nitric oxide synthase (NOS)-generating nitric oxide (NO), which mediates oxidative stress and apoptosis. Physiological expression of NOS corresponds to a constant sarcolemmal staining pattern for neuronal NOS (nNOS) and a patchy sarcolemmal and weak sarcoplasmic labeling for the endothelial NOS-isoform, with no expression for inducible NOS (iNOS). Denervated muscle displayed distinct downregulation of nNOS with preserved expression of dys…
Effects of intermittent high frequency electrical stimulation on denervated EDL muscle of rabbit.
1990
This study was performed to determine whether electrical stimulation can retard denervation-induced changes. The denervated extensor digitorum longus of the rabbit, a fast-twitch muscle, was stimulated at a rate mimicking its motoneuron firing pattern. The 100-Hz stimulation given intermittently subjected the muscle to a low mean total daily frequency of 1.6 Hz. Four weeks of stimulation resulted in no effect upon the denervated stimulated muscle. This stimulation protocol, therefore, is unable to substitute for the lost neuronal influence of the nerve. The muscle contralateral to the stimulated side showed physiological changes making it unsuitable to serve as a control.