Open AccessEvidence in Rat and Mouse Liver for Temporal Control of Two Forms of Cytochrome P ‐450 Inducible by 2,3,7,8‐Tetrachlorodibenzo‐ p ‐dioxin
Author(s) -
GUENTHNER Thomas M.,
NEBERT Daniel W.
Publication year - 1978
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1978.tb12697.x
Subject(s) - cytochrome , acetanilide , protein subunit , cytochrome p450 , chemistry , medicine , microbiology and biotechnology , endocrinology , biology , biochemistry , enzyme , gene , organic chemistry
In the liver of perinatal rats or mice, the ratio of 2,3,7,8‐tetrachlorodibenzo‐ p ‐dioxin‐induced aryl hydrocarbon hydroxylase to total cytochrome P ‐450 content decreases, whereas the ratio of 2,3,7,8‐tetrachlorodibenzo‐ p ‐dioxin‐induced acetanilide 4‐hydroxylase to total cytochrome P ‐450 content increases, between 18 or 19 days and 22 days following conception. The ontogenesis of inducible aryl hydrocarbon hydroxylase corresponds well with increases in a 56000‐ M r electrophoretic band; we suggest this band represents the cytochrome P 1 ‐450 subunit. The later temporal expression of inducible acetanilide 4‐hydroxylase closely parallels 2,3,7,8‐tetrachlorodibenzo‐ p ‐dioxin‐induced increases in size of a 54000‐ M r electrophoretic band and a 2–3‐nm hypsochromic shift in the Soret peak of the total microsomal reduced cytochrome P ‐450 · CO complex. We suggest this band represents the cytochrome P ‐448 subunit. Previous work from this laboratory has shown that this developmental difference is separated by several weeks in rabbit liver, as compared with several day's separation shown in this report with rat or mouse liver. The data here therefore provide evidence in the rodent for temporal control of the expression of different structural gene products regulated by the Ah locus.