Superoxide anion radical production in different animal species

The general objective of this study was to examine the relationship between oxygen free radicals and the aging process. The rate of superoxide anion radical (O2.-) generation was measured in liver sub-mitochondrial particles from mouse, rat, rabbit, pig and cow, and in flight muscle sub-mitochondrial particles from the housefly. The rate of O2.- generation was determined as superoxide dismutase inhibitable reduction of ferricytochrome c in the presence of antimycin A and KCN. O2.- generation was inversely related to maximum species life span potential (MLSP) (r = -0.92). A 24-fold difference in the rate of O2.- production was observed between the cow and the fly while a 6-fold difference existed among the mammals. The results are interpreted to indicate that under identical conditions, mitochondria from organisms with low MLSP have a relatively greater propensity to generate O2.-. This may be suggestive of innate differences in the molecular organization of the inner mitochondrial membrane among different species.