Calcium and Contractility: Smooth Muscle

1 Structure of Smooth Muscle.- 1. Introduction.- 2. Organization and Arrangement of Smooth Muscle.- 2.1. Organization of the Uterus and Arrangement of the Myometrium.- 3. Morphology of the Smooth Muscle Cell.- 3.1. Size and Shape of Smooth Muscle Cells.- 3.2. Plasma Membrane.- 3.3. Sarcoplasmic Reticulum.- 3.4. Mitochondria and Other Organelles.- 3.5. Myofilaments.- 4. Innervation of Smooth Muscle.- 4.1. Innervation of the Myometrium.- 5. Structure of Cultured Cells.- 6. Localization of Ca2+ in Smooth Muscle.- 6.1. Precipitating Agents, Dyes, and Autoradiography.- 6.2. Electron Probe and Electron Energy Loss Analysis of Smooth Muscle.- References.- 2 Calcium Antagonists and Ionophores.- 1. Introduction.- 2. Calcium Channel Antagonists.- 2.1. Pharmacology.- 2.2. Structure-Activity Relationships.- 2.3. Sites of Action.- 3. Calcium lonophores.- 4. Summary.- References.- 3 Calcium Compartments and Mobilization During Contraction of Smooth Muscle.- 1. Introduction.- 2. Calcium Entry.- 2.1. Intrinsic Ca2+ Leak.- 2.2. Ca2+ Entry Stimulated by Membrane Depolarization.- 2.3. Receptor-Stimulated Ca2+ Entry.- 2.4. Role of Surface Bound Ca2+.- 3. Release of Intracellularly Bound Ca2+.- 3.1. Agonist-Induced Release of Cai.- 3.2. Caffeine-Induced Release of Cai.- 3.3. Ca2+-Induced Release of Cai.- 4. Modulation of Intracellular Ca2+ Sequestration.- 4.1. Ca2+ Sequestration During Relaxation.- 4.2. Agonist-Induced Alterations in Intracellular Ca2+ Sequestration.- 5. Summary.- References.- 4 Mechanisms of Smooth Muscle Relaxation.- 1. Introduction.- 2. Relaxation Mediated by Direct and Indirect Actions on Smooth Muscle.- 2.1. Actions at the Cell Membrane.- 2.2. Intracellular Actions.- 2.3. Involvement of Endothelium in Relaxation of Vascular Tissue.- 3. Mechanisms of Relaxation.- 3.1. Relaxation Through Interaction with Cyclic Nucleotides.- 3.2. Relaxation by Interaction with Calmodulin Entry.- 3.3. Relaxation Through Blockade of Calcium Entry.- 4. Concluding Remarks.- References.- 5 Smooth Muscle Relaxants.- 1. Introduction.- 2. Beta-Adrenoceptor Agonists.- 2.1. Isoproterenol.- 2.2. Selective Beta2-Adrenoceptor Agonists.- 3. The Xanthines.- 3.1. Pharmacological Actions.- 3.2. Pharmacokinetics.- 3.3. Toxicities and Side Effects.- 3.4. Therapeutic Uses.- 4. Alpha-Adrenoceptor Antagonists.- 4.1. Prazosin.- 5. Calcium-Channel Antagonists.- 5.1. Verapamil.- 5.2. Nifedipine.- 5.3. Diltiazem.- 5.4. Perhexiline.- 6. Nonspecific Vasodilators.- 6.1. Organic Nitrates and Nitrites.- 6.2. Hydralazine.- 6.3. Diazoxide.- 6.4. Sodium Nitroprusside.- 6.5. Minoxidil.- References.- 6 Cell-to-Cell Communication in Smooth Muscle.- 1. Introduction.- 2. Cell-to-Cell Junctions.- 2.1. Structural Studies.- 2.2. Methods for Quantification of Gap Junctions.- 2.3. Functional Studies of Gap Junctions.- 2.4. Regulation of Gap Junctions.- 3. Myometrial Gap Junctions.- 3.1. Presence of Myometrial Gap Junctions.- 3.2. Function of Myometrial Gap Junctions.- 3.3. Regulation of Gap Junctions in the Myometrium.- 4. Summary.- References.- 7 Calcium Regulation of Smooth Muscle Actomyosin.- 1. Introduction.- 2. Components of the Contractile Apparatus.- 2.1. Thick Filament.- 2.2. Thin Filament.- 3. Proteins Involved in the Phosphorylation and Dephosphorylation of Myosin.- 4. Effect of Phosphorylation of Myosin Light-Chain on the Properties of Myosin.- 4.1. Functional Changes.- 4.2. Structural Changes.- 5. Effect of Tropomyosin on the Actin-Activated ATP Hydrolysis.- 6. Direct Effect of Mg2+ and Ca2+ on Actin-Activation of Phosphorylated Myosin.- 7. Evidence for the Actin-Linked System in the Regulation of Actomyosin ATPase.- 8. Summary.- References.- 8 Studies on Skinned Fiber Preparations.- 1. Introduction.- 2. Methodology.- 2.1. Skinning Procedures.- 2.2. Criteria for Acceptable Models.- 3. Intracellular Ca2+ Store.- 4. Control of Actomyosin Interaction.- 4.1. Mechanism of Ca2+ Activation.- 4.2. Cyclic Nucleotides in Smooth Muscle Relaxation.- 4.3. Catch Mechanism.- 5. Effect o... Mehr