Urinary excretion of carnitine in progressive muscular dystrophy

Abstract

ABNORMAL fat metabolism in the muscles of patients with progressive muscular dystrophy is one possible explanation for the aetiology of this genetic disease but the nature of this abnormality, if any, is not known. In dystrophic mice, the skeletal muscles affected are defective in oxidising fatty acids, but can increase synthesis^1–3. In this disease, carnitine might be expected to be involved in the impaired fatty acid metabolism, because it is of major importance in the oxidation of long-chain fatty acids as it transports them to the mitochondrial sites where they are oxidised^4–6. If there were a carnitine deficiency, fatty acid oxidation would be impaired, resulting in an excessive synthesis of triglyceride from unoxidised substrate. To examine whether carnitine is involved in the pathogenesis of progressive muscular dystrophy, urinary excretion of carnitine was estimated in patients suffering from generalised muscular atrophy of various aetiologies.