Hydrocarbon hydroxylation system in liver microsomes from four animal species.

The in vitro metabolism of n-heptadecane was investigated using hepatic microsomes from Hubbard chickens, New Zealand rabbits, Wistar rats and rainbow trout. Incubations with the 14C-labelled alkane for 1 hr showed that the rate of oxidation varied between species; the rate (per mg protein) in chickens was roughly 20-fold greater than the rate in trout, and roughly 10-fold greater than the rates in rats and rabbits. On the basis of cytochrome P-450 content, the rate of heptadecane metabolism was roughly 20-fold greater in the chicken than in the other species. Moreover, the lambda max Soret band of the reduced cytochrome P-450 CO-complex was observed at 452 nm in the chicken. Correlation between the rate of heptadecane metabolism and in vivo storage levels is discussed.