Maternal separation influences hepatic drug-metabolizing CYP450 gene expression without pathological changes in adult mice.

Objectives: The principal motive of this study is to explore the influence maternal separation (MS) exhibits on the mRNA expression of major drug metabolizing-cyp450s in parallel with the assessment of pathological changes that can be induced by MS in the livers of experimental mice.

Methods: Eighteen Balb/c mouse pups, comprising of both males and females, were separated from their mothers after birth. Following a six-week period during when the pups became adults, the mice were sacrificed and their livers were isolated for analysis of weight, pathohistological alterations, and the mRNA expression of drug metabolizing cyp450 genes: cyp1a1, cyp3a11, cyp2d9, and cyp2c29.

Results: The study demonstrated that MS markedly downregulated (p<0.05) the mRNA expression of all tested drug-metabolizing cyp450s in livers of female and male mice. Furthermore, the mRNA levels of major drug-metabolizing cyp450s were notably lower (p<0.05) in livers of female MS mice as compared with male MS mice. It was found that values of the total body weight and liver weight of MS mice did not vary significantly (p>0.05) from those of the control groups. Additionally, histological examination revealed that the hepatic tissue of MS mice was normal, similar to that of the control mice.

Conclusions: In summary, MS downregulates the gene expression of major hepatic drug-metabolizing cyp450s without inducing pathological alterations in the livers of mice. These findings provide an explanation for the heterogeneity in pharmacokinetics and drug response of patients with early life stress.