Contents: List of contributors. Section I: General Aspects of Hormones and Hormone Actions The biosynthesis of steroid hormones: an update (D.B. Gower). Overview of molecular aspects of steroid hormone actions (R.J.B. King). Gene regulation by steroid hormones (M.G. Parker). Characterisation, assay and purification of steroid receptors (M.A. Blankenstein and E. Mulder). Mechanism of action of thyroid hormone (J. Nunez). Mechanism of thyroid hormone (T.J. Visser). Characterisation of membrane receptors: some general considerations (L.E. Reichert, Jr.). Metabolism and intracellular processing of protein hormones (A.S. Khanna and D.M. Waisman). Internalisation of peptide hormones and hormone receptors (D.L. Segaloff and M. Ascoli). Physiological aspects of luteinising hormone releasing factor and sex steroid actions: the interrelationship of agonist and antagonist activities (A.E. Wakeling). Section II: Specific Actions of Steroid Hormones The functions of testosterone and its metabolites (W.I.P. Mainwaring, S.A. Haining and B. Harper). Oestrogen actions (R.L. Sutherland, C.K.W. Watts and C.L. Clarke). Glucocorticoid receptor actions (U. Gehring). Progesterone action and receptors (N.L. Krett, D.P. Edwards and K.B. Horwitz). The pleiotropic vitamin D hormone (L. Cancela, G. Theofan and A.W. Norman). Subject Index.