Brief overview of selected aspects of testicular hormone action.

This paper is designed to give an overview of the mechanism of androgen action and some of the factors that can affect it. The discussion of androgen action includes androgen transport in the blood, metabolism, receptor binding, nuclear activation and selected aspects of biological response. The importance of recognizing interspecies and interstrain differences in specific aspects of androgen action is mentioned. Some examples of the effects of environmental agents on androgen metabolism, receptor binding and biological response are included.