In 1980, the IVth International Cyclic Nucleotide Conference was held in Brussels. As this meeting attracted many investigators involved in cyclic nucleotides and calcium role in intracellular regulation, it was thought that this opportunity could be used to organize, prior to the Congress, an in-depth introductory course on the subject. This was carried out as a NATO Advanced Study Institute. The participants included Ph. D. students and M. D. s engaged in a research training, but also fully trained and well known researchers who wanted a refresher course on the whole subject. During the course, most of the participants and lecturers asked to be provided with a text summarizing the basic lectures of the course. This book was therefore conceived as a basic textbook on the regulation and action of intracellular signal molecules, concentrating mainly on cyclic nucleotides and calcium. It was deliberately kept at a basic level. We would therefore be happy if it could be used as an introduction for interested M. D. s or Ph. D. s working in other fields or entering this field and as a general refresher for researchers interested in the subject. For this reason, very general schemes have been asked of the authors, along with reading lists of available reviews rather than extensive bibliographies. The editors should like to thank the NATO Scientific Affairs Committee for having supported the course and Mrs. Gh. Wilmes who prepared the manuscripts. S. SWILLENS J. E.

Inhalt
Introduction: Cell Controls and Signal Molecules.- Regulation of the Responsiveness of Adenylate Cyclase to Catecholamines.- Studies of Solubilized Adenylate Cyclase.- Contribution of the Theoretical Simulation to the Mechanistic Description of a Biochemical System Application to the Adenylate Cyclase.- Guanylate Cyclase: Properties and Regulations.- a-Adrenergic and Cholinergic Control of Cyclic Nucleotide Metabolism.- Biochemical and Immunochemical Studies of the ?-Adrenergic Receptor.- Cyclic Nucleotide Phosphodiesterases.- Prostaglandins and Cyclic Nucleotides.- Cyclic Nucleotide Metabolism in Whole Cells.- Use of a Genetic Approach to Study Cyclic AMP Metabolism.- Sensitivity and Specificity of Prostanoic Derivatives Radioimmunoassays: New Strategy.- Regulation of Cellular Functions by Phosphorylation and Dephosphorylation of Proteins: An Introduction.- Regulation of Biochemical Processes Through Protein Phosphorylation and Dephosphorylation: Several Important Examples.- The Effects of Cyclic Nucleotide Derivatives on Cell Metabolism.- The Central Role of Calcium in Stimulus-Secretion Coupling: General Concepts and the Specialized Example of the Polymorphonuclear Leukocyte.- Calmodulin.- Cyclic Nucleotides and Cell Growth.- Microtubules and Microfilaments: The Cell Cytoskeleton.- Mechanism of Action of ACTH in the Adrenal Cortex.- Actions of Lutropin (LH) and cAMP in the Regulation of Testicular Steroid Production.- Regulation of Gastric Acid Secretion.- Molecular Basis of Interferon Action.- Cancer and Transformation by Retroviruses.- Intracellular Signals in Pituitary Hormone Secretion.