The effect of induction of aldolase on the livers of senescent mice

The specific activities of aldolase on cytosols isolated from the livers of 31 month old female mice were significantly lower than those isolated from 2.5 or 7.5 month old female animals. This age decrement resulted from the presence of inactive aldolase molecules as indicated by the decrease in the specific activity of the purified enzyme. Induction of aldolase in 7.5 and 31 month old animals by feeding a high fructose-no fat diet for two days resulted in an increase in the specific activity of the cytosol. The specific activity of the purified aidolase of 7.5 month old mice was not affected by induction. On the other hand, the specific activity of the purified aldolase of the induced 31 month old mice was higher than that of normal animals of the same age and was essentially the same as that of the younger animals. These data indicate that not only do altered enzymes result from post-translational modifications but such changes cannot be immediate.