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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the muscles of denervated and vitamin E-deficient rabbits the level of 3', 5'-cyclic AMP proved to decrease with a simultaneous increase in the activity of cAMP phosphodiesterase. In vivo experiments showed that at the concentration of 10(-4) cAMP was capable of retarding the release of acid phosphatase from the lysosome-rich fraction obtained from the muscles of E-deficient rabbits. Thus, in muscular dystrophy elevation of acid hydrolase activity in the skeletal muscle was due to leakage of the enzymes from the lysosomes as a result of decreased lysosome membrane stability because of decreased cAMP level.
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PMID:[Possible participation of cyclic AMP in regulating acid hydrolase activity in muscle tissue in avitaminosis E and denervation]. 18 39

This presentation reviews highlights of the first 20 years (1922-1942) of vitamin E. It begins with background information leading to identification of an antisterility factor for rats of both sexes and its acceptance into the vitamin family as vitamin E (1925). Research of the next 12 years revealed a multiplicity of deficiency manifestations: embryonic mortality, testis degeneration, encephalomalacia and exudative diathesis in the chick, and nutritional muscular dystrophy in avian and mammalian species. Toward the close of this period came the isolation of vitamin E from natural sources, determination of its empirical formula, and introduction of the designation alpha-tocopherol for vitamin E (1936). Within the next two years the structural formula of alpha-tocopherol was elucidated, its chemical synthesis accomplished, and its production from natural plant oils by molecular distillation was well established. The existence of other tocopherols with lesser degrees of biological activity became recognized. Also, the concurrent development of a chemical method for determining the vitamin E content of alpha-tocopherol in foods, body tissues and body fluids, which replaced the very laborious bioassay procedure, greatly facilitated later advances in knowledge of the distribution and nature of vitamin E.
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PMID:The first two decades of vitamin E. 32 68

Sixteen pregnant Shorthorn cows were winter-fed either oat or barley silage, both of which were low in selenium (less than .1 ppm). Two months before calving, as well as at calving and a month later, four cows on each diet were given intramuscularly a preparation containing 1360 IU of vitamin E and 30 mg selenium as sodium selenite. Barley silage lipids contained higher linoleic (33.2 versus 22.3%) and palmitic acids (32.3 versus 23.1%), and lower oleic (6.3 versus 22.1%) and linolenic acids (20.9 versus 30.9%) than oat silage. Three calves born from the untreated dams on barley silage died from nutritional muscular dystrophy by 50 days of age whereas none of the calves either from the untreated cows on oat silage or from any of the selenium/vitamin E treated cows. Milk from untreated cows fed barley silage contained a higher proportion of linoleic acid than that from treated cows or from those on oat silage. The incidence of nutritional muscular dystrophy was associated closely with ingestion by the calves of an increased amount of dietary dienoic acid. It appears an advantage to include oat silage in winter feeding programs for beef cows to reduce the risk of development of nutritional muscular dystrophy in the offspring.
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PMID:Influences of barley and oat silages for beef cows on occurrence of myopathy in their calves. 59 3

Ultrastructural repair of the morphological damages produced in nutritional muscular dystrophy was studied by refeeding dystrophic rabbits with vitamin E. Weanling (1.2 kg body weight) rabbits were fed a vitamin E-deficient diet for 24 days. Half of this group was then sacrificed and the remainder was given an initial oral dose of 50 mg of DL-alpha-tocopherol acetate and a vitamin E supplemented diet for 28 days. Control animals were fed a vitamin E supplemented diet with 50 mg of DL-alpha-tocopherol acetate per kilogram of diet. Abnormalities of dystrophic muscles included streaming Z-disk, degenerated mitochondria, fragmented sacroplasmic reticulum and development and aggregation of myelin figures. The effect of vitamin E therapy resulted in significant repair of the dystrophic muscle. Small localized sections of rehabilitated muscle revealed abnormal mitochondria and residual myelin figures.
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PMID:Rehabilitating effect of vitamin E therapy on the ultrastructural changes in skeletal muscles of vitamin E-deficient rabbits. 61 9

Rabbits fed a vitamin E-deficient diet developed severe muscular dystrophy in 3-4 wk, but they did not become anemic. Nevertheless, reticulocyte counts increased in deficient rabbits (3.2%) compared to control rabbits (0.9%), and erythroid hyperplasia was evident in the bone marrow. Comparing deficient rabbits to controls, the plasma iron concentration was lower (134.4 versus 206.6 microgram/dl); the TIBC was higher (335.9 versus 228.3 microgram/dl); the whole blood protoporphyrin concentration was higher (131.6 versus 81.7 microgram/dl); and the total iron content was lower in spleen (71 versus 153 microgram), higher in skeletal muscle (4956 versus 3054 microgram), and unchanged in bone marrow, liver, and heart. Studies of iron absorption and excretion using 59Fe showed no abnormalities in deficient rabbits. There were abnormalities of ferrokinetics, however. The half-time of disappearance of 59Fe was shorter (100.6 versus 169.4 min), the plasma iron turnover was greater (1.25 versus 0.95 mg/dl blood/day), and the reappearance of 59Fe in circulating erythrocytes at day 9 was greater (77.2% versus 57.2%) in deficient rabbits. Anemia induced by phlebotomy accentuated the abnormal iron metabolism of deficient rabbits, and the animals were unable to correct the anemia. These findings show that vitamin E deficiency in rabbits causes abnormal erythropoiesis associated with abnormal iron metabolism and sequestration of iron in skeletal muscle.
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PMID:Abnormalities of iron metabolism and erythropoiesis in vitamin E-deficient rabbits. 65 27

1. For methods of vitamin E and selenium supplementation were evaluated using thirty-nine pregnant ewe-lambs fed on a ration containing 0.043 mg Se/kg and 25 mg vitamin E/kg. Treatments were control, fortified mineral mix (ESe salt) (300 mg vitamin E, 3 mg Se), ruminal Se pellets (505 mg Se), drench (300 mg vitamin E, 3 mg Se) and intramuscular injection (600 mg vitamin E, 3 mg Se). Only ewes supplemented, commencing approximately 50 d before parturition. 2. Birth weights were similar for all treatments and live-weight gains of lambs to 56 d of age were improved in all supplemented groups (P less than 0.05). There were no clinical cases of nutritional muscular dystrophy. 3. Se concentrations in whole blood were more than doubled in both lambs and ewes drenched or injected; responses to ESe salt and pellets were much smaller. 4. Plasma tocopherol levels were increased in injected dams and their lambs (P less than 0.001). 5. Haemoglobin concentration and erythrocyte counts were significantly higher (P less than 0.01) in control ewes and lambs than in treated lambs. 6. Lactate dehydrogenase (EC 1.1.1.27), creatine kinase (EC 2.7.3.2) and aspartate aminotransferase (EC 2.6.1.1) activities were increased in lambs from control, ESe salt and pellet groups (P less than 0.001). Glutathione peroxidase (EC 1.11.1.9) activity responded to Se supplementation in both ewes and their lambs (P less than 0.001) and the response was highest in the injected group, followed in order, by the drench, pellet, Ese salt and control groups. 7. These studies indicated that in terms of the haematological and blood chemistry changes investigated, the intramuscular injection was most effective, followed by the oral drench. Ruminal pellets and fortified salt were less satisfactory.
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PMID:Haematological and blood chemistry changes in ewes and lambs following supplementation with vitamin E and selenium. 69 59

Rats fed a vitamin E-deficient diet for 7--8 weeks postweaning showed no change in brain weight or the activity in brain of various enzymes involved in neurotransmitter synthesis and metabolism. Body and muscle weights were markedly reduced. Muscle choline acetyltransferase and acetylcholinesterase activities were significantly elevated on a protein basis, but the total amount of choline acetyltransferase/muscle was essentially normal and total acetylcholinesterase activity was slightly reduced. Total carnitine acetyltransferase and butyrylcholinesterase activities were markedly decreased. The results are quite different from those found in hereditary murine muscular dystrophy and suggest a myogenic etiology for the vitamin E-deficiency-induced condition.
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PMID:Cholinergic systems in muscle and brain in vitamin E-deficient rats. 74 Jan 30

We are still a long way from discovering an unequivocal pathogenetic interpretation of progressive muscular dystrophy in man. Noteworthy efforts have been made in the experimental field; a recessive autosomic form found in the mouse seems to bear the closest resemblance to the human form from the genetic point of view. Myopathy due to lack of vitamin E and myopathy induced by certain viruses have much in common anatomically and pathologically with the human form. The authors induced myodystrophy in the rat by giving it a diet lacking in vitamin E. The pharmacological characteristics of vitamin E and the degenerative changes brought about by its deficiency, especially in the muscles, are illustrated. It is thus confirmed that the histological characteristics of myopathic rat muscle induced experimentally are extraordinarily similar to those of human myopathy as confirmed during biopsies performed at the Orthopaedic Traumatological Centre, Florence. The encouraging results obtained in various authoratative departments in myopathic patients by using anabolizing steroids have encouraged the authors to investigate the beneficial effects of one anabolizing agent (Dianabol, CIBA) at high doses in rats rendered myopathic by a diet deficient in vitamin E. In this way they obtained appreciable changes in body weight (increased from 50 to 70 g after forty days at a dose of 5 mg per day of anabolizing agent), but most of all they found histological changes due to "regenerative" changes in the muscle tissue, which however maintained its myopathic characteristics in the control animals that were not treated with the anabolizing agent. The authors conclude by affirming the undoubted efficacy of the anabolizing steroids in experimental myopathic disease, but they have reservations as to the transfer of the results into the human field, where high dosage cannot be carried out continuously because of the effects of the drug on virility; because the tissue injury too often occurs at an irreversible stage vis-a-vis the "regeneration" of the muscle tissue; and finally because the dystrophic injurious agent is certainly not the lack of vitamin E but something as yet unknown.
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PMID:Experimental progressive muscular dystrophy and its treatment with high doses anabolizing agents. 75 3

Pigs which were deficient in vitamin E and/or selenium had the following parameters weekly determined from six to 13 weeks of age: Packed cell volume, hemoglobin concentration, red cell and white cell counts, red cell indices, reticulocyte count, serum iron, serum total iron binding capacity, myeloid: erythroid ratio, serum glutamic-oxaloacetic transaminase and creatine phosphokinase activities and body weight. Except for the myeloid:erythroid ratio and serum creatine phosphokinase activity, these parameters were not found to be significantly affected by either vitamin E deficiency, selenium deficiency or deficiency of both. The myeloid:erythroid ratio was increased (p less than 0.01) in association with selenium deficiency, which tends to indicate decreased erythropoiesis but was not reflected in the peripheral red cell picture. Evidence of dyserythropoiesis was not found to be a significant feature in serial bone marrow aspiration biopsies of vitamin E and/or selenium deficient pigs. Even if the serum glutamic-oxaloacetic transaminase activities were not found to be significantly affected by either vitamin E deficiency, selenium deficiency or deficiency in both as compared to replete animals, a few animals, especially in the group deficient in both vitamin E and selenium, presented quite marked transient increases of serum glutamic-oxaloacetic transaminase activity which was interpreted to reflect the occurrence of acute episodes of hepatosis dietetica. Serum creatine phosphokinase activities were found to be increased in association with vitamin E deficiency (p less than 0.01), selenium deficiency (less than 0.05) and the interaction was also significant (p less than 0.01). It was concluded that the serum creatine phosphokinase activity increases reflect the occurrence of subclinical muscular dystrophy and that vitamin E and selenium deficiencies have marked additive effects in the induction of skeletal muscular dystrophy.
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PMID:Studies on vitamin E and selenium deficiency in young pigs. I. Hematological and biochemical changes. 83 88

There is good evidence that abnormal calcium accumulation may be a final common pathway of muscle degeneration in the muscular dystrophies. Prostaglandins are able to promote calcium entry into cells and excess prostaglandin activity coupled with a defect in intracellular calcium release could cause toxic accumulations of calcium in intracellular organelles such as mitochondria. Serotonin stimulates prostaglandin synthesis while tricyclic antidepressants inhibit calcium release from intracellular organelles thus possibly accounting for the models of muscular dystrophy reported using this combination. The prostaglandin/calcium hypothesis can account for the effects of vitamin E, steroids and local anaesthetic-like drugs in muscular dystrophy. Since many drugs already in clinical use for other purposes can be used to control prostaglandin synthesis or action this hypothesis has immediate potential clinical applications.
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PMID:The roles of prostaglandins and calcium accumulation in muscular dystrophy. 89 91


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