Influence of androgens and age on androgen receptor and 5α-reductase II transcription

Objective: The regulation of the androgen receptor (AR) and 5α-reductase II (5RII) gene in genital skin fibroblasts is of particular interest in understanding androgen-dependent embryonic formation of external male genitalia. Design: Human genital skin fibroblasts from pre- and postpubertal male individuals (aged 5 months to 51 years) were incubated with testosterone and dihydrotestosterone under various conditions to study the regulation of AR and 5RII transcript concentrations dependent on androgen concentration and donor age. Methods: A competitive reverse transcribed PCR (RT-PCR) protocol was designed to achieve simultaneous relative quantification (semi-quantification) of AR and 5RII mRNAs in standardized whole RNA samples from each donor. Results: Concentrations of AR and 5RII mRNAs are not influenced by androgens in genital skin fibroblasts. Moreover, comparison of AR transcript concentrations in genital skin fibroblast cell lines revealed weak variations independent of donor age, while 5RII transcription exhibited clear individual differences with a declining tendency towards higher ages. Conclusions: The transcription of AR and 5RII is not directly regulated by testosterone or dihydrotestosterone in pre- or postpubertal human genital skin fibroblasts. However, donor age seems to play a role in gradual depression of 5RII transcription.