The Enzymes

This book, dedicated to the memory of Dr. Walter B. Cannon, is an excellent review of the problems of chemical transmission in the nervous system. The first section deals with chemical transmission at autonomic neuroeffector junctions. It omits some important topics, such as supersensitivity of denervated structures, because they have been treated by the author in another recent book. Emphasis is given to the transmission in the two systems-adrenergic and cholinergic-and problems concerning liberation, generalized effects, and mode of action of chemical mediators are discussed in different chapters. The first section deals also with the theory of excitatory and inhibitory sympathins, the distribution of autonomic nerves, and the properties of smooth muscles, and ends with theories of transmission in autonomic neuroeffector systems, accepting the fact that the release of chemical agents is the exclusive way for transmission. Twelve years have passed since the appearance of the monograph Autonomic Neuroeffector Systems by Dr. Cannon and Dr. Rosenblueth, and in this period of time the theme which constitutes a brief chapter in the first book-transmission in peripheral synapses-has developed so much that it constitutes the entire second section of the present book. As a theory of the mechanism of peripheral synaptic transmission, it is accepted that acetylcholine is the essential transmitter; K ions would be an important adjuvant, and the spike potential has the limited but important action of determining the release of acetylcholine. Dr. Rosenblueth presents theories without dogmatism, and he discusses them in an exciting manner. This technique of writing offers great flexibility and allows the reader to adopt a personal opinion about the theories of chemical transmission. Nevertheless, in some of the chapter, as in the account of the action of potassium ions, it would be interesting to have more criticism concerning the role of potassium referring to other papers, as for example, those by Lorente de No. The style of the book permits easy reading, an especially hard task to accomplish in controversial problems. Summaries at the end of each chapter and also at the end of each section help to state the most important facts in the sometimes elaborate discussion of contradictory experiments. An excellent bibliography comprising 720 papers is included, and also a comprehensive subject and author index. J. DELGADO