A time-sequence study of the relationship of peroxidation, lysosomal enzymes, and nutritional muscular dystrophy

Abstract

Removal of supplemental methionine from a vitamin E-deficient diet of 3-week-old chicks precipitated symptoms of muscular dystrophy within 48 hours. Concurrent increases occurred in peroxidation in the muscles, as measured by TBA index, and in the lysosomal enzyme, β-glucuronidase. Recovery from dystrophy was faster following resupplementation of the basal diet with methionine than with addition of vitamin E. Peroxidizability of the tissues remained high in the chicks receiving the vitamin E-deficient diet even though muscular dystrophy was cured by addition of methionine. Vitamin E caused an immediate improvement in peroxidizability of tissues, yet was slower than methionine in its effect upon dystrophy. Thus peroxidizability of the tissues was not correlated with the recovery from dystrophy as effected by methionine. Lysosomal enzyme concentration in the muscles rose sharply immediately after methionine resupplementation and then regressed with recovery. The results indicated that the lysosomal enzymes are not directly implicated in the cause of nutritional muscular dystrophy; their increase apparently is involved in the hydrolytic breakdown and removal of degradative products from the tissues. The finding that methionine was completely effective, not only in prevention but also in reversion of nutritional muscular dystrophy under conditions of high peroxidizability of the muscle tissues, re-emphasizes the primary role of the sulfur amino acids in prevention of nutritional muscular dystrophy in the chick.