Inverse correlation between species life span and specific cytochrome P-448 content of cultured fibroblasts

The quantity and type of microsomal cytochrome P-450 was determined in early passage cultured fibroblasts from six mammalian species of widely differing life spans. The proportion of cytochrome P-450 and P448 varied considerably among species, with the shorter-lived species having a preponderance of cytochrome P-448. There was a good inverse correlation between potential species life span and the specific cytochrome P-448 content of cultured fibroblasts.