Age-Dependent Regulation by Androgens of Gene Expression in the Anterior Hypothalamus and Stress-Induced Release of Adrenal Hormones in Adolescent and Adult Male Rats

The study investigated how testosterone regulates gene expression in the anterior hypothalamus and stress-induced adrenal hormone release in adolescent and adult male rats. It found that adolescents had higher post-stress corticosterone levels than adults, despite similar testosterone levels. Testosterone replacement increased corticosterone in post-pubertal adolescents but decreased it in adults. The age difference in corticosterone release was attributed to different testosterone conversion pathways: adolescents converted more testosterone to oestradiol, while adults converted more to dihydrotestosterone. Inhibiting aromatase reduced corticosterone in adolescents, while inhibiting 5α-reductase or using an androgen receptor antagonist increased it in adults. These findings suggest that developmental changes in testosterone synthesis and gene regulation contribute to age-related differences in stress responses.