This book describes the evolution of ideas relating to the mechanism of muscular contraction since the discovery of sliding filaments in 1954. An amazing variety of experimental techniques have been employed to investigate the mechanism of muscular contraction and relaxation. Some background of these various techniques is presented in order to gain a fuller appreciation of their strengths and weaknesses. Controversies in the muscle field are discussed along with some missed opportunities and false trails. The pathway to ATP and the high energy phosphate bond will be discussed, as well as the discovery of myosin, contraction coupling and the emergence of cell and molecular biology in the muscle field. Numerous figures from original papers are also included for readers to see the data that led to important conclusions. This book is published on behalf of the American Physiological Society by Springer. Access to APS books published with Springer is free to APS members.
This book describes the evolution of ideas relating to the mechanism of muscular contraction since the discovery of sliding filaments in 1954. An amazing variety of experimental techniques have been employed to investigate the mechanism of muscular contraction and relaxation. Some background of these various techniques is presented in order to gain a fuller appreciation of their strengths and weaknesses. Controversies in the muscle field are discussed along with some missed opportunities and false trails. The pathway to ATP and the high energy phosphate bond will be discussed, as well as the discovery of myosin, contraction coupling and the emergence of cell and molecular biology in the muscle field. Numerous figures from original papers are also included for readers to see the data that led to important conclusions. This book is published on behalf of the American Physiological Society by Springer. Access to APS books published with Springer is free to APS members.
Understanding the molecular mechanism of muscle contraction started with the discovery that striated muscle is composed of interdigitating filaments which slide against each other. Sliding filaments and the working-stroke mechanism provide the framework for individual myosin motors to act in parallel, generating tension and loaded shortening with an efficient use of chemical energy. Our knowledge of this exquisitely structured molecular machine has exploded in the last four decades, thanks to a bewildering array of techniques for studying intact muscle, muscle fibres, myofibrils and single myosin molecules. After reviewing the mechanical and biochemical background, this monograph shows how old and new experimental discoveries can be modelled, interpreted and incorporated into a coherent mathematical theory of contractility at the molecular level. The theory is applied to steady-state and transient phenomena in muscle fibres, wing-beat oscillations in insect flight muscle, motility assays and single-molecule experiments with optical trapping. Such a synthesis addresses major issues, most notably whether a single myosin motor is driven by a working stroke or a ratchet mechanism, how the working stroke is coupled to phosphate release, and whether one cycle of attachment is driven by the hydrolysis of one molecule of ATP. Ways in which the theory can be extended are explored in appendices. A separate theory is required for the cooperative regulation of muscle by calcium via tropomyosin and troponin on actin filaments. The book reviews the evolution of models for actin-based regulation, culminating in a model motivated by cryo-EM studies where tropomyosin protomers are linked to form a continuous flexible chain. It also explores muscle behaviour as a function of calcium level, including emergent phenomena such as spontaneous oscillatory contractions and direct myosin regulation by its regulatory light chains. Contraction models can be extended to all levels of calcium-activation by embedding them in a cooperative theory of thin-filament regulation, and a method for achieving this grand synthesis is proposed. Dr. David Aitchison Smith is a theoretical physicist with thirty years of research experience in modelling muscle contractility, in collaboration with experimental groups in different laboratories.
Assessment of cardiac energetics at the level of ATP-synthesis, chemomechanical energy transformation and whole organ dynamics as a function of haemodynamic load, ventricular configuration and oxygen- and substrates supply is basic to understanding cardiac function under physiological and pathophysiological (hypertrophy, hypoxia, ischaemia and heart failure) conditions. Moreover, cardiac energetics should be an important consideration in the choice and application of drugs especially in the case of vasodilators, inotropic agents and in cardioprotective measures. Only by considering energetics at the subcellular, cellular, and whole-heart level we can arrive at a better understanding of cardiac performance and ultimately better clinical judgement and drug therapy. Quantification of myocardial energetics will also help to determine the optimal time for surgical interventions such as valvular replacement or aneurysm resection. The present volume is the outcome of an international symposium on cardiac energetics held in Gargellen/Montafon (Austria), June 1986. The contributions will certainly help bridge the existing gap between basic research involving isolated structures and that involving the whole organ, on the one hand, and render the results derived from basic research applicable to clinical problems, on the other hand.
The extremely potent substance botulinum neurotoxin (BoNT) has attracted much interest in diverse fields. Originally identified as cause for the rare but deadly disease botulism, military and terrorist intended to misuse this sophisticated molecule as biological weapon. This caused its classification as select agent category A by the Centers for Diseases Control and Prevention and the listing in the Biological and Toxin Weapons Convention. Later, the civilian use of BoNT as long acting peripheral muscle relaxant has turned this molecule into an indispensable pharmaceutical world wide with annual revenues >$1.5 billion. Also basic scientists value the botulinum neurotoxin as molecular tool for dissecting mechanisms of exocytosis. This book will cover the most recent molecular details of botulinum neurotoxin, its mechanism of action as well as its detection and application.
The second edition of Fundamentals of Anaesthesia builds upon the success of the first edition, and encapsulates the modern practice of anaesthesia in a single volume. Written and edited by a team of expert contributors, it provides a comprehensive but easily readable account of all of the information required by the FRCA Primary examination candidate and has been expanded to include more detail on all topics and to include new topics now covered in the examination. As with the previous edition, presentation of information is clear and concise, with the use of lists, tables, summary boxes and line illustrations where necessary to highlight important information and aid the understanding of complex topics. Great care has been taken to ensure an unrivalled consistency of style and presentation throughout.
