Chronic Denervation Myopathy

2021 ◽  
pp. 181-188
Author(s):  
Ahmed Bamaga ◽  
Maher Kurdi
Keyword(s):  
Author(s):  
Leonardo Hernández

The influence of Ca2+ and other divalent cations on contractile responses of slow skeletal muscle fibers of the frog (Rana pipiens) under conditions of chronic denervation was investigated.Isometric tension was recorded from slow bundles of normal and denervated cruralis muscle in normal solution and in solutions with free calcium concentration solution or in solutions where other divalent cations (Sr2+, Ni2+, Co2+ or Mn2+) substituted for calcium. In the second week after nerve section, in Ca2+-free solutions, we observed that contractures (evoked from 40 to 80 mM-K+) of non-denervated muscles showed significantly higher tensions (p<0.05), than those from denervated bundles. Likewise, in solutions where calcium was substituted by all divalent cations tested, with exception of Mn2+, the denervated bundles displayed lower tension than non-denervated, also in the second week of denervation. In this case, the Ca2+ substitution by Sr2+ caused the higher decrease in tension, followed by Co2+ and Ni2+, which were different to non-denervated bundles, as the lowest tension was developed by Mn2+, followed by Co2+, and then Ni2+ and Sr2+. After the third week, we observed a recovery in tension. These results suggest that denervation altering the binding capacity to divalent cations of the voltage sensor.


2001 ◽  
Vol 172 (2) ◽  
pp. 398-406 ◽  
Author(s):  
Ahmet Höke ◽  
Hong S. Sun ◽  
Tessa Gordon ◽  
Douglas W. Zochodne

1984 ◽  
Vol 62 (7) ◽  
pp. 849-853 ◽  
Author(s):  
W. Wayne Lautt ◽  
Anne M. Carroll

Topical application of 90% phenol around the bile duct, portal vein, and hepatic artery, as well as along each of the three hepatic ligaments was tested for effectiveness of rapid and chronic denervation in cats. Because phenol produces nonselective nerve degeneration, it was assumed that proof of functional sympathectomy was adequate proof of disruption of parasympathetic and afferent nerves as well. Functional sympathetic neurons were evaluated by measuring physiological responses to direct electrical stimulation of the anterior hepatic plexus. Acute or rapid denervation was assessed by the degree of rise in portal blood pressure produced by nerve stimulation. Complete denervation appeared within 20 min and was still present by 80 min postapplication. Chronic denervation was tested by applying the phenol and recovering the cats for 6–14 days. An equal number (n = 6) of sham-denervated cats were compared. Phenol denervation did not alter basal glucose, insulin or glucagon levels, hematocrit, blood pressure, or hepatic glycogen levels. These variables are a good index of stress and metabolic status. Nerve stimulation in the chronic sham group raised portal pressure, arterial pressure, and blood glucose levels, whereas the chronic-denervated group showed no responses. The health of the two groups appeared normal with the sole difference being that the painted itssues were mildly discolored and more adhesions appeared in the phenol-denervated set. Thus phenol is a useful tool for producing hepatic denervation. It is less traumatic, faster, and more certain than surgical denervation. In addition, the hepatic lymphatics can be preserved using the topical application of phenol.


2001 ◽  
Vol 47 (3) ◽  
pp. 194-206 ◽  
Author(s):  
Charles H. Washabaugh ◽  
Martin P. Ontell ◽  
Jeffrey A. Kant ◽  
Monica J. Daood ◽  
Jon F. Watchko ◽  
...  

1978 ◽  
Vol 235 (4) ◽  
pp. F286-F290 ◽  
Author(s):  
W. S. Spielman ◽  
H. Osswald

In contrast to the postocclusive hyperemia of brain, heart, and skeletal muscle, the hemodynamic response of the kidney following renal artery occlusion is highly variable in that both hyperemia and ischemia have been reported. The present study evaluates the factors influencing the renal response to complete renal artery occlusion (5-60 s) in the anesthetized cat. Marked postocclusive vasoconstriction could only be domonstrated in meclofenamate-treated (10 mg/kg) cats. The delta% renal blood flow (RBF) (30-s occlusion) was 16 +/- 4 in controls and 54 +/- 4 after meclofenamate (n= 10; P less than 0.001). Chronic denervation of the kidney, alpha-adrenergic receptor blockade, or infusion of [Sar1, Ile8]angiotensin II(2 microgram/min per kg) did not affect the postocclusive reduction of RBF, indicating that the vasoconstriction was independent of renal nerves, catecholamines, and circulating angiotesin II. Adenosine injected into the renal artery of five cats caused a dose-dependent transient fall of RBF. A dose of 100 nmol adenosine reduced RBF by 44 +/- 6% whereas after meclofenamate only 1 nmol produced the same degree of vasoconstriction. In summary, this study demonstrates a marked potentiation of the postocclusive vasoconstrictor response and the vasoconstrictive action of adenosine by meclofenamate in the anesthetized animal. No evidence was obtained to support a role for the sympathetic nervous system or circulating angiotensin II in mediating the postocclusive vasoconstriction.


1978 ◽  
Vol 36 (4) ◽  
pp. 316-318 ◽  
Author(s):  
M. A. Pagano ◽  
G. G. Aristimuño ◽  
Susana Basso ◽  
A. Colombi ◽  
R. E. P. Sica

An electromyographical investigation of 80 patients with chronic Chagas' disease was made. It was found that 79% of the studied patients had EMG manifestations of old and chronic denervation of the upper and lower limbs without clinical features of nervous system involvement.


Biomaterials ◽  
2021 ◽  
pp. 121244
Author(s):  
Philip J. Hanwright ◽  
Chenhu Qiu ◽  
Jennifer Rath ◽  
Yang Zhou ◽  
Nicholas von Guionneau ◽  
...  

1985 ◽  
Vol 100 (1) ◽  
pp. 161-174 ◽  
Author(s):  
U Carraro ◽  
D Morale ◽  
I Mussini ◽  
S Lucke ◽  
M Cantini ◽  
...  

During several months of denervation, rat mixed muscles lose slow myosin, though with variability among animals. Immunocytochemical studies showed that all the denervated fibers of the hemidiaphragm reacted with anti-fast myosin, while many reacted with anti-slow myosin as well. This has left open the question as to whether multiple forms of myosin co-exist within individual fibers or a unique, possibly embryonic, myosin is present, which shares epitopes with fast and slow myosins. Furthermore, one can ask if the reappearance of embryonic myosin in chronically denervated muscle is related both to its re-expression in the pre-existing fibers and to cell regeneration. To answer these questions we studied the myosin heavy chains from individual fibers of the denervated hemidiaphragm by SDS PAGE and morphologically searched for regenerative events in the long term denervated muscle. 3 mo after denervation the severely atrophic fibers of the hemidiaphragm showed either fast or a mixture of fast and slow myosin heavy chains. Structural analysis of proteins sequentially extracted from muscle cryostat sections showed that slow myosin was still present 16 mo after denervation, in spite of the loss of the selective distribution of fast and slow features. Therefore muscle fibers can express adult fast myosin not only when denervated during their differentiation but also after the slow program has been expressed for a long time. Light and electron microscopy showed that the long-term denervated muscle maintained a steady-state atrophy for the rat's life span. Some of the morphological features indicate that aneural regeneration events continuously occur and significantly contribute to the increasing uniformity of the myosin gene expression in long-term denervated diaphragm.


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