Aromatase over expression transgenic murine models for aromatase inhibitor studies.

In recent years the emerging importance of estrogen signaling in males in addition to its major role in the female reproductive system became highlighted. Aromatase is the key enzyme for synthesis of estrogens from androgens and is responsible for controlling the androgen/estrogen ratio. Inhibition of aromatase gene expression can be achieved in different ways and is important for the treatment of several estrogen-dependent diseases, such as breast cancer in females or gynecomastia/breast cancer in males, or for non-tumorigenic conditions like precocious puberty and the induction of ovulation. The inhibition of aromatase could also serve as a tool for studying the role of estrogens during development or adulthood. Using transgenic models, we are able to analyze in more detail the involvement of aromatase in the molecular mechanisms underlying the essential balance of the androgen/estrogen ratio. In this review we focus on male phenotype characterization in the aromatase overexpressing transgenic murine models and how these models can further serve as a tool for aromatase inhibitor research.