Regulation of Smooth Muscle Contraction


Book Description

Sixth Annual Graduate Hospital Research Symposium REGULATION OF SMOOTH MUSCLE PROGRESS IN SOLVING THE PUZZLE Every so often a scientific conference comes at a time when everyone has new and exciting information, when old "dogmas" do not seem to be as well established, and when speakers and participants alike are ready to challenge interpretations of old and new experimental data. This was such a conference. What turns on a smooth muscle cell? The precise answer to this question has eluded scientists for much longer than I have been involved in the field. We know that an increase in cytosolic calcium is necessary and we know that phosphorylation of the 20 kDa myosin light chain is an important step in the process. We do not know if other processes are necessary for the initiation and lor maintenance of a smooth muscle contraction nor do we know if other processes modulate the regulation of contraction. The goal of the symposium on which this volume is based was to explore the most current hypotheses for the answers to these questions. I believe that after reading the chapters included in this volume, you will agree that this goal was achieved. The importance of calcium and calmodulin dependent myosin light chain phosphoryla tion in the regulation of smooth muscle contraction was reinforced by many presentations. However, the status of myosin light chain phosphorylation as a simple calcium dependent switch came under serious suspicion.




Biochemistry of Smooth Muscle Contraction


Book Description

This valuable resource provides a systematic account of the biochemistry of smooth muscle contraction. As a comprehensive guide to this rapidly growing area of research, it covers the structure and characteristic properties of contractile and regulatory proteins, with special emphasis on their predicted function in the live muscle. Also included in this book are intermediate filament proteins, and desmin and vimentin, whose function in smooth muscle is unknown; and several enzymes involved in the phosphorylation-dephosphorylation of contractile and other proteins.




Anatomy and Physiology


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Colonic Motility


Book Description

Three distinct types of contractions perform colonic motility functions. Rhythmic phasic contractions (RPCs) cause slow net distal propulsion with extensive mixing/turning over. Infrequently occurring giant migrating contractions (GMCs) produce mass movements. Tonic contractions aid RPCs in their motor function. The spatiotemporal patterns of these contractions differ markedly. The amplitude and distance of propagation of a GMC are several-fold larger than those of an RPC. The enteric neurons and smooth muscle cells are the core regulators of all three types of contractions. The regulation of contractions by these mechanisms is modifiable by extrinsic factors: CNS, autonomic neurons, hormones, inflammatory mediators, and stress mediators. Only the GMCs produce descending inhibition, which accommodates the large bolus being propelled without increasing muscle tone. The strong compression of the colon wall generates afferent signals that are below nociceptive threshold in healthy subjects. However, these signals become nociceptive; if the amplitudes of GMCs increase, afferent nerves become hypersensitive, or descending inhibition is impaired. The GMCs also provide the force for rapid propulsion of feces and descending inhibition to relax the internal anal sphincter during defecation. The dysregulation of GMCs is a major factor in colonic motility disorders: irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and diverticular disease (DD). Frequent mass movements by GMCs cause diarrhea in diarrhea predominant IBS, IBD, and DD, while a decrease in the frequency of GMCs causes constipation. The GMCs generate the afferent signals for intermittent short-lived episodes of abdominal cramping in these disorders. Epigenetic dysregulation due to adverse events in early life is one of the major factors in generating the symptoms of IBS in adulthood.




Mechanisms of Vascular Disease


Book Description

New updated edition first published with Cambridge University Press. This new edition includes 29 chapters on topics as diverse as pathophysiology of atherosclerosis, vascular haemodynamics, haemostasis, thrombophilia and post-amputation pain syndromes.




Excitation-Contraction Coupling and Cardiac Contractile Force


Book Description

How is the heartbeat generated? What controls the strength of contraction of heart muscle? What are the links between cardiac structure and function? How does our understanding of skeletal and smooth muscle and non-muscle cells influence our thinking about force development in the heart? Are there important species differences in how contraction is regulated in the heart? How do the new molecular data fit together in understanding the heart beat? What goes wrong in ischemia, hypertrophy, and heart failure? This book paints a modern `portrait' of how the heart works and in this picture the author shows a close-up of the structural, biochemical, and physiological links between excitation and contraction. The author takes the reader through a series of important, interrelated topics with great clarity and continuity and also includes many useful illustrations and tables. The book starts by considering the cellular structures involved in excitation-contraction coupling and then described the characteristics of the myofilaments as the end effector of excitation-contraction coupling. A general scheme of calcium regulation is described and the possible sources and sinks of calcium are discussed in simple, but quantitative terms. The cardiac action potential and its many underlying currents are reviewed. Then the characteristics of some key calcium transport systems (calcium channels, sodium/calcium exchange and SR calcium uptake and release) are discussed in detail. This is then built into a more integrated picture of calcium regulation in succeeding chapters by detailed discussions of excitation-calcium coupling mechanisms (in skeletal, cardiac, and smooth muscle), the interplay between calcium regulatory processes, and finally mechanisms of cardiac inotropy, calcium overload, and dysfunction (e.g., ischemia, hypertrophy, and heart failure). Excitation-Contraction Coupling and Cardiac Contractile Force – Second Edition is an invaluable source of information for anyone who is interested in how the heart beat is controlled and especially suited for students of the cardiovascular system at all levels from medical/graduate students through senior investigators in related fields.




Regulation and Contraction of Smooth Muscle


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Signal Transduction and Smooth Muscle


Book Description

All hollow organs, such as blood vessels, the gastrointestinal tract, airways, male and female reproductive systems, and the urinary bladder are primarily composed of smooth muscle. Such organs regulate flow, propulsion and mixing of luminal contents and storage by the contraction and relaxation of smooth muscle cells. Smooth muscle cells respond to numerous inputs, including pressure, shear stress, intrinsic and extrinsic innervation, hormones and other circulating molecules, as well as autocrine and paracrine factors. This book is a review of smooth muscle cell regulation in the cardiovascular, reproductive, GI, and other organ systems with emphasis on calcium and receptor signaling. Key selling features: Focuses on smooth muscles of different types Describes ion channel signaling mechanisms Reviews calcium and receptor signaling Includes novel, cutting-edge methodologies Summarizes studies of mice with genetically encoding sensors in smooth muscle Chapter 9 of this book is freely available as a downloadable Open Access PDF under a CC-BY 4.0 license. https://s3-us-west-2.amazonaws.com/tandfbis/rt-files/docs/Open+Access+Chapters/9781498774222_oachapter9.pdf




Anatomy & Physiology


Book Description

A version of the OpenStax text




Vascular Pharmacology: Cytoskeleton and Extracellular Matrix


Book Description

Vascular Pharmacology: Cytoskeleton and Extracellular Matrix, Volume 81, contains the latest information on the vascular cytoskeleton and extracellular matrix that is presented with helpful illustrations and supporting references by prominent scientists and highly-recognized experts in the vascular field. Topics of interest in this new release include Pharmacology of the Vascular Cytoskeleton and Extracellular Matrix, The Dynamic Actin Cytoskeleton in Smooth Muscle, The Role of the Actin Cytoskeleton in the Regulation of Vascular Inflammation, The Smoothelin Family of Proteins and the Smooth Muscle Cell Contractile Apparatus, Smooth Muscle Cytoskeletal Network Regulates Expression of the Profibrotic Genes PAI-1 and CTGF, and more. - Presents a must-read book on the vascular cytoskeleton and extracellular matrix - Contains up-to-date information on the structure, function and development of the vascular cell cytoskeleton - Includes contributors from prominent scientists and highly-recognized experts with major accomplishments in the fields of the vascular cytoskeleton, extracellular matrix, mechanotransduction and vascular remodeling