Nutritional Dystrophy Research Articles

Cardiac myopathies in neonatal lambs: histological and histochemical studies.

White muscle disease (WMD), a selenium-responsive cardiac myopathy in neonatal lambs has been described from southern Iran. 15 lambs in terminal condition were referred to our lab. All the lambs were observed with the affected hearts. The lambs examined were between the postnatal ages of 1 week and 3 months. Gross changes included chalky-white appearance of entire endocardium of right ventricle and subendocardial plaques in the interventricular septum and left ventricular wall. Histologically the affected myofibrils showed swelling, acidophilia, fragmentation, segmental and patchy myonecrosis, round muscle cell nuclei, loss of sarcoplasm and sarcolemmal collapse. Purkinje fibers were relatively unaffected. Histochemical studies including Von Kossa and other stains indicated marked deposition of calcium salts in the cytoplasm of the damaged myofibrils. Calcium salts appeared as uniform, fine granules in relation to individual fiber striations. It appears that rapid accumulation of calcium into the damaged cells possibly interferes with the mitochondrial activity. As mitochondria bind excessive calcium, their capacity to respire and phosphorylate is depressed thus causing myocardial necrosis. The cardiac myopathy noted in our investigation is probably due to selenium deficiency in the soil of southern Iran. When selenium was given, it resulted in the fast recovery of the affected neonatal lambs. Moreover, no further cases of this disease (WMD) were reported after such treatments.

Rehabilitating effect of vitamin E therapy on the ultrastructural changes in skeletal muscles of vitamin E-deficient rabbits

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-α-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-α-tocopherol acetate per kilogram of diet. Abnormalities of dystrophic muscles included streaming Z-disk, degenerated mitochondria, fragmented sarcoplasmic 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

New developments in muscle pathology: Nutritional myopathies including “muscular dystrophy” or “white muscle disease”

Dietary deficiencies of vitamin E and/or selenium may result in muscular degeneration in young calves and older growing animals. The preservation and storage of moist grain with propionic acid reduces its vitamin E content; feeding such grain to older animals may predispose them to the myodegeneration which often occurs following their return to spring grazing and unaccustomed exercise. Cold or wet windy weather may be another predisposing factor. Deficiency of vitamin E or selenium probably results in peroxidative damage to cell membranes which precedes tissue and muscular degeneration.

Influences of Barley and Oat Silages for Beef Cows on Occurrence of Myopathy in Their Calves

Sixteen pregnant Shorthorn cows were winter-fed either oat or barley silage, both of which were low in selenium (<.l 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 30mg 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 died 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.

Morphological changes in skeletal muscles in vitamin E-deficient and refed rabbits.

1. Nutritional muscular dystrophy was induced in young rabbits by giving them a vitamin E-deficient diet. Dystrophic animals were rehabilitated by the addition of vitamin E to the diet. Controls were fed on a supplemented diet containing 50 mg DL-α-tocopheryl acetate/kg.2. Muscle weight and fibre diameter were determined in seven skeletal muscles, from the fore-limb (biceps brachii), the trunk (pectoralis descendens), the hind-limb (gastrocnemius, semitendinosus, soleus, plantaris and tibialis cranialis). Muscle weights, except for those of the soleus and semitendinosus, were significantly reduced in vitamin E-deficient animals when compared with the control animals. A monophasic fibre diameter distribution was obtained for all muscles from all the groups studied. Distribution curves for vitamin E-deficient muscles showed a consistent decrease in fibre diameter. The extent of change in distribution varied among different muscles. On refeeding, the redistribution curve returned to the normal pattern in the biceps brachii, semitendinosus, gastrocnemius, plantaris, tibialis cranialis and pectoralis descendens but not in the soleus.3. No significant changes in bone length or weight were detected in the humerus, femur and tibia in vitamin E-deficient rabbits compared to the control animals.4. Transverse and longitudinal sections of the seven muscles were studied by light microscopy. In the vitamin E-deficient animals, typical hyaline degeneration was observed with much infiltration of collagen and lymphocytes. The extent of degeneration varied among muscles, the gastrocnemius being most affected and the semitendinosus least affected. Muscles in the rabbits refed vitamin E showed that the infiltration with collagen and lymphocytes had almost disappeared.

Oxidative Deterioration of the Muscle Proteins during Nutritional Muscular Dystrophy in Chicks

Nutritional muscular dystrophy in the chick results from the simultaneous deficiency of vitamin E and cystine. Being a biological antioxidant, vitamin E might be functional in maintaining a proper redox state of the sulfur-containing amino acid in the proteins. The analyses of protein-bound sulfhydryls and disulfides at onset of muscular dystrophy in young chicks were carried out. The ratio of disulfide to sulfhydryls increased two- to three-fold in dystrophic muscle as compared to that in the control muscle proteins. Dystrophic and normal muscle proteins also were subjected to SDS-gel electrophoresis. Proteins of low molecular weight, supposedly derived from proteolysis, were present in the gels of the dystrophic muscle and absent in those of normal muscle extracts. As a result of these studies, a chemical model has been proposed to explain the oxidative deterioration of proteins in nutritional muscular dystrophy due to vitamin E deficiency.

White muscle disease of sheep and associated tissue selenium levels in Western Australia.

White Muscle Disease of sheep occurs in Western Australia as distinct syndromes in lambs and weaner sheep. Mean liver selenium concentrations of lambs and weaners with WMD and unaffected by WMD were 0.19 and 0.46 ppm, and 0.20 and 0.41 ppm (dry weight) respectively. There was considerable overlap between levels suggesting that selenium status was not the only factor involved in the development of WMD.

Effects of Selenium and Vitamin E Deficiencies on Reproduction, Growth, Blood Components, and Tissue Lesions in Sheep Fed Purified Diets

Three 2 X 2 factorial experiments were conducted with sheep fed purified diets to determine the effects of selenium and vitamin E on the incidence of white muscle disease (WMD) and blood components. All lambs reaching 6 weeks of age in the group receiving no vitamin E or selenium developed WMD lesions, whereas only a few lambs in either the +E - Se or -E + Se treatment groups developed these lesions. Plasma activities of creatine phosphokinase, lactic dehydrogenase and glutamic oxaloacetic transaminase were significantly elevated in lambs receiving no vitamin E or selenium, whereas these enzyme activities in those receiving only selenium were non-significantly elevated. The enzyme activities in plasma of those on the +E - Se or +E + Se treatments were maintained at low levels, suggesting vitamin E alone is more effective in preventing WMD than selenium alone. The metabolic interactions of these essentials are discussed.

Selenium and white muscle disease in woodchucks.

Gross and histologic examination of wood chcks (Marmota monax) trapped on farms in Central New York revealed white muscle disease(WMD). The concentration of selenium in the animal tissues, vegetation and soils in the vicinity of trapping did not consistently correlate with the presence of WMD.

Effects of Selenium and Vitamin E on Blood Selenium Levels, Tissue Glutathione Peroxidase Activities and White Muscle Disease in Sheep Fed Purified or Hay Diets

The effects of selenium and vitamin E on blood selenium levels and tissue glutathione peroxidase activities were determined in sheep fed purified and hay diets. A significant increase of blood levels of this element and tissue glutathione peroxidase activities was found in sheep given selenium as compared to those not receiving this element. Of the tissues examined, the highest glutathione peroxidase activity was found in the heart. Vitamin E had no influence on either the blood selenium levels or upon the tissue glutathione peroxidase activity. With hydrogen peroxide as the substrate, tissue glutathione peroxidase activity was not correlated with the incidence of white muscle disease. Evidence is presented to suggest that 0.1 ppm dietary selenium is not sufficient under some conditions to meet the physiological requirements for this element.

Clinical Experiences with White Muscle Disease

For many years veterinarians saw clinical cases and read reports of primary myopathic diseases in food animals and the equine. During the 1950's and the 1960's, investigative research teams found one of the probable causes to be a deficiency of either alpha tocopherol and/or selenium in the diet. Since this breakthrough, innumerable clinical manifestations of white muscle disease (WMD), selenium responsive disease (SRD), or selenium alpha tocopherol deficiency (STD) have been encountered.

Selenium, vitamin E and copper in multiple sclerosis.

There has been accumulation of the nutritional muscular dystrophy of the cattle in a certain western district of Finland where the prevalence of multiple sclerosis (MS) is also highest. This animal disease is due to lack of selenium (Se) and vitamin E. The Se content of whole blood was low (52.6 +/- 11.3 ng/ml) in MS patients from this high-risk area compared to the controls (68.8 +/- 11.0). The data for serum failed to confirm this tendency. All Se values appeared to be lower than international values suggested. The values for both vitamin E and copper were within the international normal range.

Selenium in soils, pastures and animal tissues in relation to the growth of young sheep on a marginally selenium-deficient area

Abstract Extract Selenium-responsive diseases of farm animals in New Zealand have been reviewed by Andrews et al. (1968). In sheep these may be manifested as infertility in ewes, as “congenital” or “delayed” white muscle disease in lambs, or as unthriftiness, a condition usually more apparent in young animals. As evidenced by weight responses of lambs to dosing with selenium salts, selenium-responsive unthriftiness has occurred widely in New Zealand (Robertson and During, 1961). Most investigations into selenium-responsive conditions, e.g., Cousins and Cairney, 1961; Hartley, 1967; A. B. Grant, pers. comm.) have related mainly to areas that could be described as severely selenium-deficient.

The effects of selenium on the metabolism of methionine in sheep

Two groups of sheep fed a diet of hay known to produce nutritional muscular dystrophy, one group of which received selenium supplementation, were used to study the effects of selenium on the metabolism of administered L-(35S) methionine by rumen microflora. Rumen bacterial proteins of the Se supplemented sheep contained significantly higher levels of radiosulfur than the bacterial protein of the non-supplemented sheep. Of hte L-(35S) methionine present in the rumen liquor samples from Se-supplemented sheep 2 h after administration, 13.3% of the amino acid, which was measured as methionine sulfone, was found in the microbial proteins. A large proportion of the administered labeled methionine was resynthesized as cyst(e)ine which may account in part for that determined as cysteic acid in rumen bacterial and plasma proteins. The observed low levels of radiosulfur found in rumen microflora from selenium deficient wethers, indicates that the presence of selenium profoundly affects the rate of methionine metabolism and the distribution of methionine in rumen bacterial and protozoal proteins. In another experiment, the effect of selenium on the metabolism of L-(Me-3H) methionine was studied. The selenium status of the sheep had no significant effect (P greater than 0.05) on the distribution of 35S radioactivity in the blood plasma and tissues.

Selenium content of feeds and effect of dietary selenium on hair and blood serum.

A selenium depletion diet (.025 ppm selenium) was fed to two male Holstein calves for its effect on concentrations of selenium in serum. By 90 days, selenium in serum was depressed from .022 ppm to .013 ppm, and one of two calves had died of "possible white muscle disease." Repletion was rapid in that a diet containing .200 ppm selenium increased selenium in serum to .028 ppm within 2 wk. Dietary .280 ppm selenium increased it to .051 ppm in 1 wk. Eleven cows and eleven calves showed averages of .030 ppm in serum (range of .013 to .051 ppm) fed a diet of corn silage (.039 ppm) and supplement (.090 ppm). A sampling of feedstuffs showed a wide range of selenium among feedstuffs (.023 for corn cobs to 2.663 ppm for dried egg albumin) and a wide range within one type feedstuff (shelled corn, .017 to .219 ppm).

Studies on the Changes in Reduced Glutathione of Chick Tissues during Onset and Regression of Nutritional Muscular Dystrophy

Nutritional muscular dystrophy (NMD) in the chick results from a simultaneous deficiency of vitamin E and cystine. Muscle and liver of dystrophic and nondystrophic chicks were assayed for nonprotein sulfhydryl (NP-SH), reduced glutathione (GSH) and glutathione reductase. Red blood cells were assayed for NP-SH and GSH content. Glutathione peroxidase was determined in muscle, plasma and liver. Dystrophic muscle GSH was increased and at times was approximately double that of normal muscle, while liver GSH was lower in dystrophic than in normal chicks. During recovery from NMD, brought about by addition of either vitamin E or cystine to the dystrophogenic diet, muscle GSH declined and liver GSH increased to normal levels. Glutathione peroxidase was equivalent in both dystrophic and nondystrophic plasma and liver, but was significantly increased in dystrophic muscle. The mode of action of dietary cystine in preventing NMD in chicks remains unknown; it is not mediated through the role of amino acid as a component of the GSH needed for the action of glutathione peroxidase.

Creatine phosphokinase in normal sheep and in sheep with nutritional muscular dystrophy

The distribution of CPK activity in the tissues of sheep was compared with that in the tissues of the ox, horse, pig and rat. The CPK activities found using the sensitive backward reaction in the presence of glutathione were much higher than those reported previously using less sensitive methods. It was confirmed that CPK activity is highest in skeletal muscle. The concentration of CPK activity in cardiac muscle was 13 to 56 per cent. and in the cerebrum was 5 to 11 per cent. of that in skeletal muscle in the species examined. The normal plasma activity of CPK in the pig was higher than in the sheep, ox and horse. In lambs with nutritional muscular dystrophy, plasma CPK was increased more than AspAT. Activities of both enzymes declined to normal after treatment with vitamin E or selenium, but the rate of decline of plasma CPK was more rapid.

Osmotic and oxidative haemolysis of erythrocytes in calves with white muscle disease

The stability of erythrocytes to both osmotic and oxidative haemolysis was studied in naturally occuring cases of white muscle disease of calves two to 14 weeks old. During clinical and subclinical disease the incidence of haemolysis when erythrocytes were exposed to 0-588 per cent NaCl was 74-3 +/-18-8 per cent and 76-6+/-18-6 per cent respectively, whereas in clinically healthy animals receiving 30 mg vitamin E per kg feedstuff the incidence of haemolysis was only 55-9+/-12-7 per cent. Erythrocytes of the calves receiving vitamin E supplements were completely resistent to peroxidative haemolysis whereas in the clinical and preclinical cases approximately 12-5 per cent of cells were lysed.

Whole wheat grain feeding of Merino ewes. 2. Influence of wheat and vitamin A on reproductive performance

In two experiments Merino breeding ewes were fed wheat in pens (wheat/pen) or small paddocks (wheat/paddock) from joining to weaning. Three levels of wheat were examined in each experiment (L1, M1, H1-experiment 1 ; L2, M2, H2-experiment 2) and at each wheat level a group of ewes received vitamin A. Control groups of ewes were run at pasture. The percentage of ewes pregnant in experiment 1 was higher in groups fed pasture than in groups fed wheat. There were no differences due to wheat level or vitamin A treatments. In experiment 2 there was an interaction between treatments in their effects on pregnancy rate. In experiment 2 wheat level had a linear effect on the proportion of multiple births and wheat/pen ewes gave birth to fewer twins than wheat/paddock ewes. The effects of wheat level on lamb birth weight were linear and quadratic in experiments 1 and 2 respectively. Lamb survival between birth and weaning was not influenced by wheat level or vitamin A in experiment 1. Lamb survival among groups fed wheat and pasture was 46 per cent and 84 per cent respectively. In experiment 2 there was an interaction between the treatments in lamb survival. In experiments 1 and 2, 66 per cent and 53 per cent respectively of lamb deaths among groups fed wheat were attributed to starvation. Goitre was diagnosed in 9 per cent of dead lambs from the wheat/pen groups of experiment 2. In both experiments white muscle disease was found in dead lambs from the wheat/pen groups.

Selenium-responsive unthriftiness of young merino sheep in Central Victoria.

A trial was carried out to determine whether selenium responsive unthriftiness existed on a property in the Strathbogie ranges of Central Victoria where unthriftiness of young sheep has been a problem for 10 to 20 years. White muscle disease had been diagnosed on the property in the previous year and on other properties in the area. Eighty Merino ewes and lambs were allotted to one of 4 groups in a 2 x 2 factorial designed trial in which sodium selenite (0.1 mg/kg) was given orally to ewes and/or lambs at marking time and to treated lambs at 3 monthly intervals thereafter. Selenium treatment of the ewes had no significant effect on subsequent lamb performance. Selenium treatment of the lambs produced significant responses: mortality in treated groups was 0% compared with 17.5% in untreated groups; body weight gains were 1.9 kg higher at both weaning and one year of age in treated than in untreated lambs; mean fleece weight was 14.4% higher in treated lambs and they produced 39% more wool than the surviving untreated lambs.