Steroid Hormone Action

A compilation of cutting-edge research, Neuroplasticity, Development, and Steroid Hormone Action explores the effects of steroid hormones on brain development, function, and aging. The experimental approaches used by the authors ranges from molecular to behavioral and endocrine to neurobiological. It contains scientific photographs, line drawings, tables, color illustrations, and graphs, this interesting and timely text covers the neuroplastic effects of steroid hormones throughout the lifetime of various animal models, such as bees, fish, lizards, turtles, birds, mice, rats, and primates.

The purpose of this book is to focus attention on recent developments in steroid and sterol hormone action. Many authors have generously contributed to the book. As a result, there is a great diversity of opinion! A majority of the chapters deal with steroid or sterol hormone receptors. This is not meant to imply that receptor-mediated mechanisms are the sole or even the most important mechanisms by which steroid hormones act in the cell. There is wealth of evidence showing that other, non-receptor events, are important also. Steroid hormone recep tor research and the study of nuclear events mediated by steroids are presently the most intensely studied aspects of sterol hormone action and our selection of topics reflects this trend. We have also included chapters on vitamin 0 sterols and thyroid hormone in the book, as there is pood evidence that these hormones act in a manner similar to other classical steroids. 1 IMMUNOCHARACTERIZATION OF THE NUCLEAR ACCEPTOR SITES FOR THE AVIAN OVIDUCT PROGESTERONE RECEPTOR A. GOLDBERGER, M. HORTON, T. C. SPELSBERG Department of Biochemistry and Molecular Biology, Mayo Clinic and Mayo Graduate School of Medicine, Rochester, MN 55905 INTRODUCTION It is well known that steroid hormones, certain vitamins and sterols, enter target cells and bind to specific protein receptors in the cyto plasm or nucleus (1-4). This binding is saturable, high affinity, and steroid specific.

Steroid Hormone Action is a comprehensive overview of the molecular mechanisms by which these hormones regulate the expression of specific target genes. The book covers the structure of steroid receptors, transcriptional activation and repression, and also contains chapters on steroid bindingproteins and steroidogenesis. Steroid receptors represent one of the best characterized transcription factors so that the book will be of general interest to Molecular Biologists studying eucaryotic gene regulation. Chapters on the mechanisms of action of steoid antagonists and defective receptorsin target cells will be of particular interest to Endocrinologists and Clinicians. In such a rapidly progressing field it is difficult to keep up with all the literature but this book, written by international experts, focuses on the most important advances that have been made recently.

During the last two decades, progress in steroid hormone research has resulted in the development of new approaches to contraception as well as diagnosis and treatment of endocrine disorders and cancers. Although significant advances have been made in the purification, characterization, immunochemistry and molecular biology of steroid receptors, the precise molecular mechanism of steroid hormone action has remained obscure. This book captures the detailed presentations made at the first conference on Steroid Receptors in Health and Disease held at Meadow Brook Hall, Oakland University in the fall of 1987. The purpose of this international con ference was to facilitate scientific exchange toward a better understand ing of the mode of action of steroid hormones. The scientific sessions consisted of poster presentations and state-of-the-art lectures, the latter of which make up this volume. The first chapter is meant to provide the reader with a more general background of the topics covered in the book, as well as to discuss certain theme-related issues that are either not yet well-established or accepted or are in the stage of infancy. It is hoped that this volume will serve as a useful treatise for students and investigators interested in basic and clinical aspects of biological regulation by steroid hormones. A task of this magnitude could not have been undertaken without the encouragement, advice and continued generous assistance of the members of the scientific committee. I am gratefully indebted to Drs.

This volume is an outgrowth of a symposium held at the University of Michigan, Ann Arbor, Michigan, October 27-29, 1975. This symposium was organized to bring together basic scientists and clinicians for the purpose of exchanging new ideas and the latest information in the area of Steroid Hormone Action and Cancer. The design of the symposium included both formal plenary sessions and informal roundtable discussion groups, the chapters of this volume being drawn primarily from these proceedings. During the last quarter of a century considerable progress has been made toward understanding the molecular mechanisms in volved in steroid hormone action. It now appears that the mechan sim of action of the four major classes of steroid hormones is qualitatively similar. Research during the past decade has demonstrated steroid hormone receptors in a variety of normal and neoplastic tissues. Receptor-containing neoplasms have been shown to be hormone-dependent and undergo regression when treated with hormone antagonists. Natural and synthetic steroids also have been employed for many years to successfully treat various types of cancer, for example: estrogens, androgens and progestagens for breast cancer; estrogens and progestagens for prostatic carcinoma; progestagens for endometrial carcinoma; and corticoids for leu kemias. All of these neoplasms have now been found to possess receptors for the steroids empirically used in their treatment.

The past few years have witnessed the emergence of steroid hormones as the wonder molecules which generate as much discussion in the scientific literature as they do in a typical living room. This transition has been a result of the tremendous public and scientific interest in the normal functioning of the hor mones as well their suggested involvement in several clinical conditions. In the recent past, notable scientific and technological advances have been made in the areas of contraception and regulation of fertility. Steroid receptors are the indis pensable mediators of hormonal responses and are complex protein molecules which appear to exist in association with other, yet undefined, proteins and/or factors. Receptors for vitamin D, retinoic acid and the thyroid hormones share structural similarities with steroid receptors, and the roster of this superfamily is still expanding. While our knowledge of the diversity and magnitude of steroid effects has advanced, the precise mode of steroid hormone action has alluded investigators. This volume brings together an international team of prominent investigators who discuss their most recent work on the basic and clinical aspects of steroid/nuclear receptors. The contributions represent updated versions of the invited presentations made at The Second Meadow Brook Conference on Steroid Receptors in Health and Disease. I am grateful to my colleagues on the Scientific Committee: Etienne Baulieu, Jack Gorski, Benita Katzenellenbogen, David Toft and James WittJiff, who provided the vision and guidance in formulating an out standing program.

Mechanisms of Hormone Action: A NATO Advanced Study Institute focuses on the action mechanisms of hormones, including regulation of proteins, hormone actions, and biosynthesis. The selection first offers information on hormone action at the cell membrane and a new approach to the structure of polypeptides and proteins in biological systems, such as the membranes of cells. Discussions focus on the cell membrane as a possible locus for the hormone receptor; gaps in understanding of the molecular organization of the cell membrane; and a possible model of hormone action at the membrane level. The text also ponders on insulin and regulation of protein biosynthesis, including insulin and protein biosynthesis, insulin and nucleic acid metabolism, and proposal as to the mode of action of insulin in stimulating protein synthesis. The publication elaborates on the action of a neurohypophysial hormone in an elasmobranch fish; the effect of ecdysone on gene activity patterns in giant chromosomes; and action of ecdysone on RNA and protein metabolism in the blowfly, Calliphora erythrocephala. Topics include nature of the enzyme induction, ecdysone and RNA metabolism, and nature of the epidermis nuclear RNA fractions isolated by the Georgiev method. The selection is a valuable reference for readers interested in the mechanisms of hormone action.