Aldolase B in the liver of senescent rats.

The process of enzymatic aging was studied in livers of adult and senescent rats for aldolase B. No "cross-reacting material" was found in livers of 27 to 30-month-old rats, estimated by the ratio aldolase activity-antigen amount. The activity towards the two substrates of aldolase, fructose 1,6-diphosphate and fructose 1-phosphate did not vary in senescent animals. Moreover, other physico-chemical properties of the enzyme such as thermal inactivation, immunological reactivity and Michaelis constant remain unchanged. These results provide arguments against the occurrence of errors in protein synthesis as a cause of aging.