* To whom correspondence should be addressed.
Received May 25, 2000; Revision received November 3, 2000
This review analyzes data on the biological role of 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) in animal and human tissues and describes its main characteristics, mechanism of action, and regulation of activity. Based on published data, a scheme for the actions of androgen, progestin, and glucocorticoids involving the participation of 3alpha-HSD is proposed. According to this scheme, in the mechanism of steroid action 3alpha-HSD not only regulates the concentration of the main effector androgen, 5alpha-dihydrotestosterone, in target cells, but also switches androgen, progestin, and glucocorticosteroid genomic activity to non-genomic activity.
KEY WORDS: 3alpha-hydroxysteroid dehydrogenase, structure, mechanism of action, biological role