Lipid dystrophy

Foxley, A., Edwards, R.H.T. and Jackson, M.J. (1991). Enhanced lipid peroxidation in Duchenne muscular dystrophy may be secondary to muscle damage. Biochem. Soc. Trans. 19, 1805. 

Other leukodystrophies are associated with the lysosomal and peroxisomal disorders in which specific lipids or other substances accumulate due to a deficiency in a catabolic enzyme - for example Krabbe s disease, meta-chromatic leukodystrophy (MLD) and adrenoleuko-dystrophy (ALD) [1,2]. (These are discussed in detail in Ch. 40.) Similarly, disorders of amino acid metabolism can lead to hypomyelination - for example phenylketonuria and Canavan s disease (spongy degeneration) [1, 2, 25] (Ch. 40). The composition of myelin in the genetically... 

Deficiency of vitamin E is rare it can occur from abnormalities in lipid absorption as well as dietary deficiency. Its deficiency affects the muscular system, causing dystrophy and paralysis and, if the heart is affected, death by myocardial failure. This is probably caused by demyelin-ation of axons due to oxidative damage. Vitamin E is incorporated into chylomicrons within the enterocyte, so that its uptake into cells requires the activity of lipoprotein lipase. 

Buj-Bello, A., Laugel, V., Messaddeq, N., Zahreddine, H., Laporte, J., Pellissier, J. F., et al. (2002) The lipid phosphatase myotubu-larin is essential for skeletal muscle maintenance but not for myogenesis in mice. Proc Natl Acad Sci USA 99, 15060-15065. Sullivan, T., Escalante-Alcalde, D., Bhatt, H., Anver, M., Bhat, N., Nagashima, K., et al. (1999) Loss of A-type lamin expression compromises nuclear envelope integrity leading to muscular dystrophy. J Cell Biol 147, 913-920. 

The signs of a vitamin E deficiency may be quite different in animals and humans. The signs occurring in experimental animals indude impaired reproduction and muscle weakness (muscular dystrophy). Reproductive defects in female animals involve a failure of the fetus to thrive. In males, the deficiency results in an inhibition of sperm production. One feature common to humans and animals is the formation of lesions (pathological structures) in nerves and muscles. The deficiency can cause the degeneration of nerves and the accumulation of a compound called lipofuscin in various tissues, such as muscle. Lipofuscin has an amorphous structure and is thought to be composed of lipid degradation products and croSS linked proteins. 

A few studies have appeared on various aspects of the composition of muscle lipids in diseased muscle. It has long been known from histochemical studies that in many patients with muscular dystrophy there is a huge increase in adipose tissue between the fibers, but it seems doubtful whether there is an increase in true muscle fat. Pennington et al. (P14) could find no marked abnormality in the fatty acid composition of the infiltrated fat in a case of Duchenne dystrophy when compared with normal adipose tissue. Hughes (H15, H16) has carried out extensive studies on the concentration of various classes of lipids in the various... 

Owens, K., Fatty acid and aldehyde composition of noimal and dystrophic mouse lipids. Res. Muscular Dystrophy, Proc. 4th Symp., London pp. 286-295 (1968). 

Characteristic lesions of vitamin E deficiency in animals include necrotizing myopathy (inaccurately referred to as nutritional muscular dystrophy), exudative diathesis, nutritional encephalomalacia, irreversible degeneration of testicular tissue, fetal death and resorption, hepatic necrosis, and anemia. Several of these conditions are directly related to peroxidation of unsaturated lipids in the absence of vitamin E, and others can be prevented by synthetic antioxidants or vitamin E. 

Lj sosomes Cooxidation by per-oxidizing lipid Breaking of membrane and release of hydrolytic enzymes Some of the catabolic reactions of muscular dystrophy involving protein, nucleic acid, and mucopolysaccharide hydrolysis... 

B. Effect of Peroxidizability of Muscle Lipids on Nutritional Dystrophy.. 543... 

Touboul, D., Brunelle, A., Halgand, E, De La Forte, S., Laprevote, O. (2005) Lipid imaging by gold cluster time-of-flight secondary ion mass spectrometry application to Duchenne muscular dystrophy. J. Lipid Res., 46, 1388-1395. 

The vitamin is absorbed through the intestine by a mechanism similar to that involved in the absorption of other liposoluble vitamins consequently, intestinal disorders leading to lipid malabsorption are associated with malabsorption of vitamin E. Humans with such malabsorption syndromes have reduced levels of vitamin E in their tissues. They do not show classical symptoms of muscular dystrophy, although a certain degree of muscular fatigue may be observed. 

Little is known about the role of inositol in nutrition. Inositol exhibits lipotropic activity in animals only when added to a hypolipotropic diet devoid of fat, and it exerts either no or slight activity when fat is added to the diet. Inositol has been suggested as an adjuvant in the prevention and treatment of chronic liver disease in man. It has been reported that inositol administration leads to a decrease in the level of cholesterol and lipid phosphorus in the serum of patients with diabetes mellitus. It has been postulated that inositol plays a role in creatine metabolism and therefore may be beneficial in the therapy of muscular dystrophy in conjunction with tocopherol. The value of inositol in any of the above situations remains unproved. 

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