Ebook: Regulation of Smooth Muscle Contraction

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.

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Content:
Front Matter....Pages i-xii
Tribute to Professor Edith B?lbring....Pages 1-2
Structure-Function Relationships in Smooth Muscle Myosin Light Chain Kinase....Pages 3-10
Regulation of Smooth Muscle Myosin Light Chain Kinase by Calmodulin....Pages 11-24
Regulation of Smooth Muscle Actomyosin Function....Pages 25-36
Biochemical and Functional Characterization of Smooth Muscle Calponin....Pages 37-51
Regulation of a Smooth Muscle Contraction: A Hypothesis Based on Skinned Fiber Studies....Pages 53-59
Cooperative Mechanisms in the Regulation of Smooth Muscle Contraction....Pages 61-75
Mechanics of the Crossbridge Interaction in Living and Chemically Skinned Smooth Muscle....Pages 77-84
Modulation of Ca2+ Sensitivity by Agonists in Smooth Muscle....Pages 85-96
Regulation of the Ca2+-Force Relationship in Permeabilized Arterial Smooth Muscle....Pages 97-109
Myosin Light Chain Kinase Phosphorylation: Regulation of the Ca2+ Sensitivity of Contractile Elements....Pages 111-127
Myosin Heavy Chain Isoforms and Smooth Muscle Function....Pages 129-138
Mechanical and Biochemical Events During Hypoxia-Induced Relaxations of Rabbit Aorta....Pages 139-145
Can Different Four-State Crossbridge Models Explain Latch and the Energetics of Vascular Smooth Muscle?....Pages 147-157
Calcium Homeostasis in Single Intact Smooth Muscle Cells....Pages 159-170
Pharmacomechanical Coupling: The Membranes Talk to the Crossbridges....Pages 171-183
Characteristics of the Voltage-Dependent Calcium Channel in Smooth Muscle: Patch-Clamp Studies....Pages 185-208
Changes in Cytoplasmic Calcium Induced by Purinergic P2x Receptor Activation in Vascular Smooth Muscle Cells and Sensory Neurons....Pages 209-227
Purification and Reconstitution of the Ryanodine- and Caffeine-Sensitive Ca2+ Release Channel Complex from Muscle Sarcoplasmic Reticulum....Pages 229-239
Cytosolic Calcium Ion Regulation in Cultured Endothelial Cells....Pages 241-256
Altered Excitation-Contraction Coupling in Hypertension: Role of Plasma Membrane Phospholipids and Ion Channels....Pages 257-271
Many Membrane Abnormalities in Hypertension Result from one Primary Defect....Pages 273-290
[Ca2+]i Distribution and Signalling in Vascular Hypertrophy....Pages 291-302
Control and Function of Alterations in Contractile Protein Isoform Expression in Vascular Smooth Muscle....Pages 303-314
Biophysical and Biochemical Properties of “Asthmatic” Airway Smooth Muscle....Pages 315-325
Purification of Protein Kinase C and Identification of Isozymes in Vascular Smooth Muscle....Pages 327-352
Polylysine: An Activator of Smooth Muscle Contractility....Pages 353-361
Increased ATPase Activity and Myosin Light Chain Kinase (MLCK) Content in Airway Smooth Muscle from Sensitized Dogs....Pages 363-368
Isoforms (Conformations?) of Turkey Gizzard Myosin Light Chain Kinase: Separation by Anion Exchange High Performance Liquid Chromatography....Pages 369-376
Cloning Phospholamban cDNA from Rat Aortic Smooth Muscle....Pages 377-386
Myosin Heavy Chain Isoform Patterns Do Not Correlate with Force-Velocity Relationships in Pulmonary Arterial Compared with Systemic Arterial Smooth Muscle....Pages 387-395
Detailed Balance and four State Models of Smooth Muscle Activation....Pages 397-402
Regulation of the Step-Distance in Shortening Muscles....Pages 403-413
An Analysis of Length-Dependent Active Stiffness in Smooth Muscle Strips....Pages 415-424
Effects of Muscle Length on Intracellular Ca2+ During Isometric Contraction of Tracheal Smooth Muscle....Pages 425-434
Isotonic Shortening Parameters but not Isometric Force Development are Altered in Ragweed Pollen Sensitized Canine Bronchial Smooth Muscle....Pages 435-443
Frequency Analysis of Skinned Indirect Flight Muscle From a Myosin Light Chain 2 Deficient Mutant of Drosophila Melanogaster with a Reduced Wing Beat Frequency....Pages 445-453
Control of HCO3-Dependent Exchangers by Cyclic Nucleotides in Vascular Smooth Muscle Cells....Pages 455-460
Norepinephrine Stimulates Inositol Trisphosphate Formation in Rat Pulmonary Arteries....Pages 461-472
Time-Dependent Decrease in Ca2+-Sensitivity in “Phasic Smooth Muscle”....Pages 473-479
Calcium-Dependent and Independent Mechanisms of Contraction in Canine Lingual Artery to U-46619....Pages 481-489
Mode of Action of Neurotransmitters on Depolarized Smooth Muscle....Pages 491-498
Platelet Activating Factor Causes Relaxation of Isolated Pulmonary Artery and Aorta....Pages 499-505
The Effect of Calcium Antagonist on Norepinephrine-Induced 86Rb Efflux in Obese Zucker Rats....Pages 507-515
Effects of Pinacidil, Cromakalim, and Nicorandil on Potassium Currents of Rat Basilar Artery Smooth Muscle....Pages 517-522
Back Matter....Pages 523-529
....Pages 531-541