ISSN:0148-639X    

DOI:10.1002/mus.880060103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractSkeletal muscle fibers from dystrophic mice and littermate controls (ReJ‐129) were characterized electrically and then injected with an intracellular marker. In this way they could be identified for examination with an electron microscope to correlate the relative time course of electrical and ultrastructural aherations resulting from the dystrophic process. On the average, dystrophic muscle fibers displayed decreased membrane potentials (−59 ± 1.2vs−79 ± 0.7 mV for normals), decreased specific membrane resistivity (517 ± 27vs642 ± 34 Ω‐cm2for normals), and depressed action potential (AP) maximum rates of rise (+Vmax) (352 ± 9vs417 ± 9 V/s for normals) and amplitudes (92 ± 1.2vs102 ± 1.0 mV for normals) at an experimentally polarized membrane potential of −90 mV. Membrane resistivity and AP +Vmaxwere decreased even in those fibers from dystrophic muscles that displayed normal ultrastructure (classified visually and by ratio of sarcoplasmic reticulum to total cell volume). These findings support the membrane hypothesis of muscular dystrophy that membrane lesions are the primary lesion in t

ISSN:0148-639X    

DOI:10.1002/mus.880060104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe trophic influences of nerve and muscle on one another were studied in normal and dystrophic littermates of C57BL/6Jdy2Jmice parabiosed at 20 to 23 days after birth. Each parabiont had a soleus muscle cross‐reinnervated by a tibial nerve of its partner. Ultrastructural abnormalities of muscle and endplate were quantified and compared 6 to 7 months postoperatively. The dystrophic nerve degenerated despite reinnervation to a normal muscle. The normal muscle did not prevent the dystrophic nerve from degenerating, and the dystrophic nerve induced degenerative changes in the reinnervated normal muscle. Normal nerve did not retard the genetically programmed degeneration of the dystrophic muscle. The dystrophic muscle, however, did not appear to cause normal nerve terminals to degenerate. We conclude that both nerve and muscle cells in dystrophic mice express characteristics of muscular dystrophy. Muscle fibers of a few motor units further suffer from abnormal neurotrophic influence because of the degeneration of the motor neurons. Myotrophic influence on nerve was not observe

ISSN:0148-639X    

DOI:10.1002/mus.880060105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractA study of the soleus muscle of the rat along its entire length during the first week following tenotomy was undertaken. Within the first few days the affected fibers of the soleus underwent a complete morphological reorganization. Portions of fibers near the tendons were Invaded by and replaced with a large population of phagocytes. Previous studies have implied that the number of sarcomeres in series is reduced, but it has not been demonstrated from what portion of the fiber the sarcomeres are revoved. Sections of fibers taken from the mid‐belly region demonstrated a progressive degenerative process over the first few days. Myofibrils across the entire width of the affected fibers underwent dissolution and degeneration. Fibers with central core lesions could be found by the seventh day after tenotomy, however, at this stage the peripheral myofibrils were new, and the fibers had begun the regenerative process which continued until normal fiber histology was restore

ISSN:0148-639X    

DOI:10.1002/mus.880060106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThirty‐nine human skeletal muscle biopsies from 24 individuals were classified as normal, neuropathic, or myopathic muscle according to classical clinical observations and histopathological properties of the muscles. The content in myosin light chains (LC) of each muscle sample was analyzed by means of a new technique of polyacrylamide gel electrophoresis that gives an improved discrimination, involving isoelectrofocusing of the muscle homogenate for the first dimension and successive migration in a urea‐containing gel for the second dimension. Four different LC patterns have been observed in the normal muscles; these four patterns and three different ones have been observed in the pathological muscles. No apparent correlation exists between the myosin LC content and the histochemical fiber typing. It is concluded that the myosin LC are apparently not a useful marker to detect the normality or the pathology of human mus

ISSN:0148-639X    

DOI:10.1002/mus.880060107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractSingle muscle fibers from a typical case of hypokalemic periodic paralysis (HOPP) have been found to be depolarized in all test media and to be cathodally blocked after exposure to insulin. The diseased fibers also bind more insulin and consume more oxygen than controls. The hypothesis proposed is that increased amount or affinity of insulin binding on the HOPP muscles causes continual depolarization in the presence of normally subthreshold concentrations of circulating insulin. This is because of steady effects of the hormone on passive K+and Na+fluxes. Additional insulin causes rapid further depolarization with paralysis. Hypokalemia follows if the insulin increment is enough to stimulate active K+and Na+transport.

ISSN:0148-639X    

DOI:10.1002/mus.880060108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractAn animal model of defective muscle glycolysis can be produced by intra‐aortic injection of iodoacetate which blocks the glycolytic enzyme glyceraldehyde‐3‐phosphate dehydrogenase. The animals show exercise‐induced, electrically silent muscle cramps and postexercise rhabdomyolysis. Exercised, cramped soleus and extensor digitorum longus muscles from these animals show marked depletion of the high energy compounds adenosine triphosphate (ATP) and creatine phosphate and accumulation of fructose‐1, 6‐diphosphate. This finding supports the hypothesis that exercise‐induced muscle contracture and cell damage in disorders of muscle glycolysis/glycogenolysis are the result of depletion of high energy molecules in the

ISSN:0148-639X    

DOI:10.1002/mus.880060109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractDecreasing the temperature from 37 C to 20 C in vitro reactivates muscle twitch in response to nerve stimulation in a muscle previously paralyzed by botulinum toxin. Transmitter release calculated as quantum content of endplate potentials has an extremely enhanced sensitivity to temperature in botulinum paralysis (Q10about 45) compared to normal muscle blocked by high magnesium concentration (Q10about 2). This difference is not caused by increased efficacy of the calcium mechanism of transmitter release in botulinum poisoning at low temperature, as demonstrated by unaltered calcium‐dependence of quantum content at 22 C compared to 35 C for both types of neuromuscular block. The results give exciting clues to the mode of action of botulinum toxi

ISSN:0148-639X    

DOI:10.1002/mus.880060110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThis investigation was undertaken to find out whether the structural and biochemical changes seen in skeletal muscles in congenital nemaline myopathy (CNM) occurred also in nonmuscle cells. It was confirmed that nemaline bodies contain α‐actinin. The distribution of actin and α‐actinin in the examined nonmuscle cells was considered normal. The motility of the leucocytes and the fibroblasts was indistinguishable from that of those in normal controls. Slight changes in the peripheral nerve fibers of one patient were found, but these were not seen in another patient. The results indicate that congenital nemaline myopathy is not a generalized disorder but is restricted to skeletal m

ISSN:0148-639X    

DOI:10.1002/mus.880060111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractSkeletal muscle obtained from 2 patients with congenital nemaline myopathy (CNM) and from a healthy control was analyzed by 1‐ and 2‐ dimensional gel electrophoresis. In total extracts, an increase of α‐actinin by a factor of 2:3 was found for CNM muscle as compared with the control. One‐ and two‐dimensional gels revealed the presence of LCF3, the smallest light chain associated with type 2 (fast) myosin in total extracts of normal control of mixed fiber type. Both CNM samples showed the absence of this polypeptide. This result is consistent with the finding that muscle of the 2 patients exhibited nearly exclusively the ATPase activity indicative of type 1 (sl

ISSN:0148-639X    

DOI:10.1002/mus.880060112

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY