Changes in catalase activity and its thermolability in liver and kidneys of ageing male garden lizard.

Catalase activity in liver and kidneys of male garden lizards remained unchanged during maturation, but showed an increase during ageing. Instead of inactivating catalase, thermal treatment at 60 +/- 1 degree C caused a marginal increase in enzyme activity in the liver of middle-aged and kidneys of young lizards with no significant effect in old counterparts. Increase in basal enzyme activity during ageing and the maintenance of resistance against thermal inactivation of the enzyme throughout the life-span support the contention that catalase molecules in lizard tissues are not altered as a function of age, a deviation from the predictions of Orgel's error catastrophe hypothesis.