Effect of Age on the Ability of Rat Liver Tissues to Transform Chemical Promutagens to Mutagens

Abstract

Age-related changes in drug metabolism of the liver from male Lou rats were determined by measuring changes in the production of mutagens. Activation of aflatoxin B₁ (AFB₁), 2-aminoanthracene (2AA) and benzo[a]pyrene (B[a]P) to mutagenic derivatives was assayed using the Ames salmonella test system. The promutagens were incubated with tissue fractions isolated from rats ranging in age from 3 weeks to 18 months. Hepatic activation of AFB₁ and 2AA changes with age and is maximal from 4 to 10 months. In contrast, no significant modification with age was observed for the activation of B[a]P. It is concluded that the composition of different cytochrome P-450 fractions is modified with age thereby altering the specific ability to convert different promutagens to mutagens.

Urinary polycyclic aromatic hydrocarbons as a biomarker of exposure to PAHs in air: A pilot study among pregnant women

“…However, activation of benzo [a]pyrene to mutagenic derivatives, as measured by the Salmonella typhimurium test, with hepatic microsomes from male rats from 3 weeks to 18 months of age showed no age-dependent changes (Hilali et al 1993). …”