Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Evidence to suggest the presence of abnormal metabolism of oxygen free radicals in progressive muscular dystrophy is presented using an animal model. In the superficial pectoral muscles of dystrophic chickens, enzyme activities regulating the metabolism of oxygen free radicals, i.e., catalase, superoxide dismutases and glutathione peroxidase, were significantly elevated within 1 week of hatching. Activities of related enzymes, i.e., glutathione reductase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase were also elevated. In contrast, the specific activity of phosphofructokinase, the rate-limiting enzyme of the glycolytic pathway, was normal during the first 4-week period. These results suggest that there is an increased turnover of oxygen free radicals in the dystrophic muscle. This concept appears important in a further investigation of the pathogenesis and treatment of progressive muscular dystrophies.
 ...
PMID:Pathogenesis of progressive muscular dystrophy: studies on free radical metabolism in an animal model. 336 52

Lipid peroxidation and other free radical reactions are known to disrupt and damage cellular structures and function, and it has been postulated as possible mechanisms of cellular damage of muscular dystrophy because increased levels of thiobarbituric acid (TBA)-reactive products and increased activities of superoxide dismutase and glutathione peroxidase were reported in avian muscular dystrophy. We reported that activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase were significantly increased in avian muscular dystrophy from the early developmental stage. Since these enzymes protect cellular structures from free radicals and peroxides, increased activities of these enzymes would indicate increased formation of radicals. Then it seems to be important to assay TBA-reactive products which indicate tissue malondialdehyde content, a by-product of lipid peroxidation. We used dystrophic chickens of New Hampshire series line 413 and their controls line 412 for assay of TBA-reactive products. Four or five birds from respective lines were killed by decapitation two weeks, four weeks and four months after hatching. The superficial pectoral muscle was immediately weighed and levels of TBA-reactive products in the muscle homogenate was assayed by fluorophotometry according to the modified method of Ohkawa and Tanizawa. Levels of TBA-reactive products were significantly higher in dystrophic chickens at all stages of development studied than those of the control group. At two weeks of age morphological changes are minimum if present and increased levels of TBA-reactive products cannot be considered as a secondary change of morphological alterations. Therefore, the results indicate involvement of lipid peroxidation damage in pathogenesis of this avian muscular dystrophy.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Studies on pathogenesis of muscular dystrophy: levels of thiobarbituric acid-reactive products in avian muscular dystrophy]. 674 4

The mechanisms primarily responsible for the degenerative processes occurring in dystrophic skeletal muscle remain unresolved. The identification of the mechanisms that lead to the complete sparing of extraocular muscle in dystrophinopathies is of particular interest. A number of studies have provided evidence to suggest that the muscle pathology that characterizes muscular dystrophy may be, in part, free radical mediated. In the present study, we examined the antioxidant enzyme status of extraocular, diaphragm and gastrocnemius muscles in control strain and mdx mice. Our results revealed that in the control strain, both extraocular and diaphragm muscles had higher copper/zinc superoxide dismutase, manganese superoxide dismutase and selenium dependent glutathione peroxidase activities as compared to the gastrocnemius. Furthermore, the diaphragm had higher glutathione reductase activity as compared to the gastrocnemius. These findings indicate that the highly aerobic extraocular and diaphragm muscles have higher antioxidant enzyme capacity than the gastrocnemius, a muscle more dependent on anaerobic energy metabolism. Changes in the antioxidant enzyme status of the mdx mouse correlated, in part, with the degree of histopathological involvement of the three muscle groups assessed.
 ...
PMID:Extraocular, limb and diaphragm muscle group-specific antioxidant enzyme activity patterns in control and mdx mice. 885 50

Facioscapulohumeral muscular dystrophy (FSHD), the most frequent muscular dystrophy, is an autosomal dominant disease. In most individuals with FSHD, symptoms are restricted to muscles of the face, arms, legs, and trunk. FSHD is genetically linked to contractions of the D4Z4 repeat array causing activation of several genes. One of these maps in the repeat itself and expresses the DUX4 (the double homeobox 4) transcription factor causing a gene deregulation cascade. In addition, analyses of the RNA or protein expression profiles in muscle have indicated deregulations in the oxidative stress response. Since oxidative stress affects peripheral muscle function, we investigated mitochondrial function and oxidative stress in skeletal muscle biopsies and blood samples from patients with FSHD and age-matched healthy controls, and evaluated their association with physical performances. We show that specifically, oxidative stress (lipid peroxidation and protein carbonylation), oxidative damage (lipofuscin accumulation), and antioxidant enzymes (catalase, copper-zinc-dependent superoxide dismutase, and glutathione reductase) were higher in FSHD than in control muscles. FSHD muscles also presented abnormal mitochondrial function (decreased cytochrome c oxidase activity and reduced ATP synthesis). In addition, the ratio between reduced (GSH) and oxidized glutathione (GSSG) was strongly decreased in all FSHD blood samples as a consequence of GSSG accumulation. Patients with FSHD also had reduced systemic antioxidative response molecules, such as low levels of zinc (a SOD cofactor), selenium (a GPx cofactor involved in the elimination of lipid peroxides), and vitamin C. Half of them had a low ratio of gamma/alpha tocopherol and higher ferritin concentrations. Both systemic oxidative stress and mitochondrial dysfunction were correlated with functional muscle impairment. Mitochondrial ATP production was significantly correlated with both quadriceps endurance (T(LimQ)) and maximal voluntary contraction (MVC(Q)) values (rho=0.79, P=0.003; rho=0.62, P=0.05, respectively). The plasma concentration of oxidized glutathione was negatively correlated with the T(LimQ), MVC(Q) values, and the 2-min walk distance (MWT) values (rho=-0.60, P=0.03; rho=-0.56, P=0.04; rho=-0.93, P<0.0001, respectively). Our data characterized oxidative stress in patients with FSHD and demonstrated a correlation with their peripheral skeletal muscle dysfunction. They suggest that antioxidants that might modulate or delay oxidative insult may be useful in maintaining FSHD muscle functions.
 ...
PMID:Functional muscle impairment in facioscapulohumeral muscular dystrophy is correlated with oxidative stress and mitochondrial dysfunction. 2279 48

The most common form of muscular dystrophy is known as Myotonic dystrophy Type 1 (DM1) in adults. It was aimed to investigate the relationship between antioxidant imbalance and diaphragm thickness with pulmonary function test results in peripheral blood of Myotonic Dystrophy Type 1 patients. In the prospective study, 33 DM1 and 32 healthy control groups were taken after the ethics committee decision (2018-10529). Antioxidant defence system enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferase (GST) and thiobarbituric acid reactive species (TBARS) levels were studied in blood samples. Also, muscular strength (MRC score), creatine kinase (CK) and diaphragm thicknesses were measured, and pulmonary function tests were performed. Among the studied parameters, TBARS levels and GPX, GR and GST activities in erythrocytes of DM1 patients showed a significant decrease in the range of 29-45% compared to the control group. MRC score, diaphragm thickness and inspiratory function test results at the end of inspiration and expiration were found lower though CK levels were higher in DM1 group. In the patient group, a positive correlation was found between antioxidant parameters (TBARS, CAT and GST) with diaphragm thicknesses and pulmonary function test though GPX showed a negative correlation with them. It was emphasized that the data obtained shows the harmful/pathogenic role of oxidative stress caused by free radicals in DM1, and also provide useful data for the treatment and processes of this disease.
 ...
PMID:Antioxidant imbalance in the erythrocytes of Myotonic dystrophy Type 1 patients. 3187 Jun 60