Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Muscle Denervation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1981

[An experimental study on the functional recovery of denervated muscles--effects of stump rotation in nerve suture (author's transl)].

There are many factors which affect the end result of nerve suture. Clinically it is said tht rotation of the stumps at suture site has an unfavorable effect upon functional recovery, owing to discrepancies of funicular patterns and inappropriate funicular approximation. In order to evaluate the effect of rotation of the stumps at suture sites, tibial nerves of thirty-three full grown rabbits were used. After the tibial nerve was cut at a point three cm proximal to the popliteal fossa, in one group (20 rabbits) the nerve was sutured without rotation (0 degrees group) and in another group (19 rabbits) with 180 degrees rotation of the proximal stump (180 degrees groups), using epineural technique under operating microscope. Six months later return of nerve function was evaluated electrophysiologically and histologically. Electrophysiological measurements included electromyography, motor conduction velocity and muscle strength stimulating proximal stump. Histological evaluation following weighing included H-E stain, DPN diaphorase stain for muscle and Cajal stain for axon. There were no significant differences between the two groups with regard to the passage rate of axons at the suture site, motor conduction velocity or recovery rate of muscle weight. But muscle strength of the plantaris in the 180 degrees group was significantly weaker than that of 0 degrees group, and in the 180 degrees group, recovery rate of muscle strength was lower than that of muscle weight, though they were the same in the 0 degrees group. Histochemically there was marked fibre type grouping of the reinnervated muscle in both groups. The author concluded that in the rabbits, the rotation of nerve stumps at suture site does not affect the passage rate of axons at the suture site nor maturation of the axon. However, it does impose unfavorable influence upon functional recovery. Further problems may arise for the recovery of complex functions when reconstitution of proprioceptive feed-back system is considered.

Action Potentials↗
PubMed1980

[Reactions between 3H-monoacetylcobratoxin and membrane preparations from denervated muscles and caudate nuclei].

3H-monoacetyl derivative of the major neurotoxin of venom obtained from Naja naja oxiana was used as a marker of the nicotinic cholinoreceptor (N-ChR). It was shown that binding of neurotoxin with the membranes of bovine caudate nuclei unlike binding with the membranes of the rabbit gastrocnemius muscles is less strong and cannot be blocked completely with high concentrations of neurotoxin and d-tubocurarine. Serum of the rabbits immmunized with the protein preparation isolated from the membranes of caudate nuclei inhibited the binding of the marker by the membranes of caudate nuclei to a greater measure than by muscle membranes. It is concluded that the marker in question can be used for detecting N-ChR in caudate nuclei and that this cholinoreceptor differs from that of muscles.

Animals↗
PubMed1999

Altered gene expression in steroid-treated denervated muscle.

In rats treated with high-dose corticosteroids, skeletal muscle that is denervated in vivo (steroid-denervated) develops electrical inexcitability similar to that seen in patients with acute quadriplegic myopathy. To determine whether changes in muscle gene transcription might underlie inexcitability of steroid-denervated muscle we performed RNase protection assays to quantitate adult (SkM1) and embryonic (SkM2) sodium channel isoforms and chloride channel (CLC-1) mRNA levels in control, denervated, steroid-innervated, and steroid-denervated skeletal muscle. While SkM1 mRNA levels were relatively unaffected by denervation or steroid treatment, SkM2 mRNA levels were increased by both. These effects were synergistic and high levels of SkM2 mRNA were expressed in denervated muscle exposed to corticosteroids. Skeletal muscle CLC-1 mRNA levels were decreased by denervation. To better understand the marked upregulation of SkM2 in steroid-denervated muscle we examined changes in myogenin and glucocorticoid receptor mRNA levels. However, changes in these mRNA levels cannot account for the upregulation of SkM2 in steroid-denervated muscle.

Adolescent↗
PubMed1998

The effect of denervated muscle and Schwann cells on axon collateral sprouting.

The effects of denervated muscle and Schwann cells on collateral sprouting from peripheral nerve were studied in the peroneal and tibial nerves of 48 Sprague-Dawley rats. Three groups were prepared. In group MSW (muscle-Schwann cell-window), the peroneal nerves were transected 3 mm below the sciatic bifurcation. The proximal stumps were sealed in a blocked tube to prevent regeneration and the distal stumps were implanted into denervated muscle cells that were wrapped around the ipsilateral tibial nerve, which had a window of perineurium resected. Schwann cells from the ipsilateral sural nerve were implanted into the muscle. Group MS (muscle-Schwann cell) was similar to group MSW, except that the tibial nerve perineurium was kept intact. In group MW (muscle-window), the muscle was prepared without Schwann cells and the tibial nerve perineurium was windowed. S-100 immunostain was used to identify the Schwann cells surviving 1 week after transplantation. After 16 weeks of regeneration, horseradish peroxidase tracer was used to label motor neurons and sensory neurons reinnervating the peroneal nerve. Myelinated axons of the reinnervated peroneal nerves were quantified with the Bioquant OS/2 computer system (R&M Biometrics, Nashville, TN). A mean of 169 motor neurons in group MSW, 64 in group MW, and 26 in group MS reinnervated the peroneal nerve. In the dorsal root ganglion, the mean number of labeled sensory neurons was 1,283 in group MSW, 947 in group MS, and 615 in group MW. The mean number of myelinated axons in the reinnervated peroneal nerve was 1,659 in group MSW, 359 in group MS, and 348 in group MW. Reinnervated anterolateral compartment muscles in group MSW were significantly heavier than those in group MS or MW. This study demonstrates that the transplantation of denervated muscle and Schwann cells promotes motor and sensory nerve collateral sprouting through a perineurial window.

Animals↗
PubMed1974

The sensitivity to glutamate of denervated muscles of the crayfish.

The effect of denervation on the sensitivity of muscle fibres to glutamate was studied in leg muscles of crayfish.1. When the motor nerve was cut close to the proximal accessory flexor muscle the distal end of the nerve degenerated. Neuromuscular transmission failed and spontaneous miniature potentials disappeared after two months. Several stages of nerve terminal degeneration were seen in muscles denervated between 1 and 3 months, and after 4 months no remains of synapses could be found.2. Following denervation for periods up to 8 months there was no significant change in sensitivity to glutamate, a substance that mimics the action of the neural transmitter. Depolarizations produced by various concentrations of glutamate in the bathing solution were the same in denervated and control muscle fibres. Moreover, the sensitivity to iontophoretically applied glutamate was localized to discrete patches as in innervated muscles.3. Supersensitivity of muscles apparently does not occur after denervation in the crayfish.

Action Potentials↗
PubMed1995

[Treatment of anal incompetence in children by free graft of denervated muscle].

Transplantation of a denervated muscle imitating a levator loop allows pathogenetic correction of anal incompetence. Its results depend on the patient's participation in the rehabilitation process to a lesser extent than the results of plastics of the external sphincter ani by the traditional methods. This is of certain significance in pediatric practice and makes it possible to operate on younger children. This method produces satisfactory results in the so-called hopeless patients suffering from meningocele and concomitant developmental anomalies of the spine. This makes it possible to widen significantly the indications for surgical treatment of children with fecal incontinence.

Adolescent↗
PubMed1982

Cell proliferation in denervated muscle: time course, distribution and relation to disuse.

The effects of denervation on skeletal muscle fibers have been intensively investigated, but the effects on other cell types within muscle tissue are not well understood. In the present experiments, cell proliferation was analyzed in mouse extensor digitorum longus muscles denervated for periods of one day to six weeks. Incorporation of tritiated thymidine into DNA increased 36 h after denervation, reached a maximum at a level twenty times control at 4 days, and returned towards control values by 7 days. Incorporation first increased in the endplate area, but 12 h later involved the entire muscle. Six weeks after denervation, muscles labeled at 4 days had lost 90% of the total label. Muscle disuse, produced by tetrodotoxin block of the nerve for up to 4 days, did not result in a proliferative response. Thus, cell proliferation after denervation is not a response to simple disuse, but rather to a nerve- or muscle-related mitogen. Since the response is mostly distributed throughout the entire muscle, the mitogen probably emanates from muscle fibers.

Animals↗
PubMed1974

Fate of alpha-bungarotoxin bound to acetylcholine receptors of normal and denervated muscle.

In organ culture, alpha-[(125)I]bungarotoxin bound to extrajunctional receptors of denervated muscle is lost from the tissue at a more rapid rate than the toxin bound to the junctional receptors of normal muscle. The rapid loss of toxin from denervated muscle can be blocked by inhibitors of energy production and protein synthesis, and may reflect turnover of the toxin-receptor complex in the membrane.

Animals↗