The Alteration of Enzymes in Aging Animals

Abstract

The earliest experiments dealing with the effect of aging on enzymes consisted of simple comparisons of activity in crude homogenates from various young and old tissues. In general, the results from different laboratories through the 1950’s and 1960’s could not profitably be compared because they were carried out with crude preparations, a variety of assays and undoubtedly there were differences between the old animals raised in different laboratories. Most of the reported changes in activity were relatively small, few being more than 30%. Some results were even contradictory - a few enzyme activities were reported both to increase and decrease. However, even if the early work had been carried out in more sophisticated fashion, it is doubtful that any insight into aging phenomena would have resulted. In fact, more recent work with carefully matched animals which measured a spectrum of enzymes from various tissues failed to show any consistent behavior which could be interpreted as being a mark of the aging process (Lindena et al, 1980). There does appear to be a generalized decline in the enzymes involved in fatty acid oxidation and the tricarboxylic acid cycle in soleus muscle and diaphragm in 24 compared with 6 month old rats and a decline in the former parameter in heart (Hansford and Castro, 1982)