New facets of the biochemistry of steroid hormone action.

Summary Some aspects of recent experimental approaches to the molecular basis of steroid hormone action are reviewed. Among the topics considered are: (1) the bearing of structure-activity relationships, and of pathways for the metabolism of steroid hormones, on the problem of the nature of the primary cellular receptors for these hormones; (2) coenzyme-like actions of sex hormones in isolated enzyme systems; (3) steroid hormones as allosteric effectors; (4) steroid hormones as regulators of gene expression and of intermediate reactions involved in nucleic acid and protein synthesis.