Glycolysis and lipid synthesis in brown adipose tissue during ageing in the rat

The maximal activity of the enzymes hexokinase and 6-phosphofructokinase were measured in interscapular brown adipose tissue during ageing in the rat. The activity of these glycolytic enzymes increased markedly during the suckling-weaning transition (20-22 days of age), but from 30 to 100 days of age the activities per gram wet weight and per mg protein decreased. The rate of lipogenesis in brown adipose tissue was also increased over the suckling-weaning transition and the contribution of glucose to this fatty acid synthesis was greater in weaned animals especially under the influence of insulin.