FIG. 1. Mechanism of androgen action. Testosterone (T) enters the cell and is converted by 5 alpha reductase to 5alpha-dihydrotestosterone (DHT). DHT binds to the androgen receptor (AR) leading to a conformational change in the protein and the dissociation of several accessory proteins, including heatshock proteins (HSP). Binding of the AR to the androgen response element (ARE), along with other transcription factors (TF) regulates the transcription of mRNAs. (From: Lindzey J, Kumar MV, Grossmann M, Young C, Tindall DJ. Molecular Mechanisms of Androgen Action. In: Litwack G, ed. Vitamins and Hormones. Orlando, Florida: Academic Press, Inc.; 1995;49:383-432.)