Changes in the muscle of weanling rats - abstract only

ABSTRACT

Weanling rats were fed on a low-protein high carbo-hydrate diet. After 4 weeks they were refed on a stock diet containing 18 percentprotein. Measurements were made of the DNA and protein content of the muscle at the end of the depletion period, at various times during recovery and also in control animals growing normally. The diet caused a virtually complete arrest of growth. Body and muscle weight remained constant at the levels reached on weaning. In muscle the ratio of nitrogen to DNA was greatly reduced; this reduction was entirely at the expense of cellular protein. The connective tissue of muscle continued to increase in amount throughout the depletion period. On refeeding in muscle there was evidence of a lag period before the synthesis of new tissue reached its maximum rate. The results tend to support the suggestion that ratio of non-collagen nitrogen to DNA in muscle may be a useful index of the degree of protein depletion. (AU)