The contributions of this volume are concerned with transport phenomena in multimembrane systems and in simple epithelia. In addition to the very substan tial progress that has been made in the area of transport of fluid and solutes across artifical model membranes in vitro and across simple symmetrical cell membranes, much has been learned from studies of transport phenomena in multi membrane systems of higher complexity to be reviewed in this volume. It should be recalled that many of the fundamental conceptual and methodological problems of transport physiology have been successfully approached and defin ed by studying simple epithelia in vitro, and that the direction that research has taken has been affected in a major way by the cellular transport models that have evolved from this approach. Since then striking progress has been made in several areas. Not only have we been witnessing a keen and productive interest in the realtionship between fine structure and transport behavior in multimem brane systems but significant advancements have also been made in defining individual active and passive transport operations, in analysing cell ion activities and transport pools, and in describing the differences in transport functions that underly the membrane asymmetry and cell polarization of cells subserving di rectional transport.
Reihe
Sprache
Verlagsort
Verlagsgruppe
Zielgruppe
Für Beruf und Forschung
Research
Gewicht
ISBN-13
978-3-540-08596-6 (9783540085966)
DOI
10.1007/978-3-642-46364-8
Schweitzer Klassifikation
1 - Transport Across Multimembrane Systems.- A. Introduction.- B. Organization of Epithelia.- I. "Black Box" Approach.- II. Transepithelial Potentials.- III. The Two-Membrane Theory for Transepithelial Potentials.- IV. Nature of the Individual Transport Processes of the Two-Membrane Model for Transepithelial Transport.- 1. The Entry Step for Sodium.- 2. Ion Selectivity of the Inward-Facing Membrane.- 3. The Sodium Pump.- C. Sodium Entry Coupled with Transport of Organic Substances.- D. Exchange Diffusion and Counter-Transport Systems in Epithelial Transport.- E. Transport of Water.- I. Reflection Coefficients of Epithelia.- II. Water Permeability Determined with Isotopic Water.- III. Effects of Unstirred Layers.- IV. The Problem of Isotonic Water Transport.- F. Hormonal Effects on Epithelial Transport.- References.- 2 - Role of Tight Junctions in Epithelial Function.- A. Introduction.- B. Ultrastructure.- I. Thin Sections.- II. Freeze Fracture.- C. Epithelial Diversity and the Paracellular Pathway.- I. Identification.- II. Evaluation.- 1. Ion Movements.- 2. Nonelectrolytes.- 3. Water.- D. Molecular Organization.- I. Tight vs. Leaky Junctions: is the Difference Molecular or Anatomical?.- II. Chemical Organization: Inferences from Ion Permeability Measurements.- 1. Inorganic Ions.- 2. Organic Cations.- E. Modification of Tight Junction Permeability.- I. Tonicity.- II. Potential Difference.- III. Chemical Agents and Physiological Conditions.- IV. Tight Junction Reconstruction and Metabolism.- F. Role of Junctional Permeability in Epithelial Transport.- References.- 3 - Morphological Correlates of Transport.- A. Introduction.- B. The Organization of Cytoplasm.- I. Water.- II. Solutes.- l. Na+and K+.- 2. H+.- 3. Ca++andMg++.- 4. CI?.- 5. Intracellular Ion Concentrations.- 6. Histochemical Localization of Ions.- 7. Microprobe Analysis.- 8. Compartmentation of Organic Solutes.- C. Pericellular Pathways.- I. Junctional Permeability in Vascular Tissues.- II. Junctional Permeability in Epithelia.- III. Freeze-Fracture Studies.- IV. Properties of the Shunt Pathway.- V. Nature of the Intercellular Cement.- VI. Perspectives on the Pericellular Pathways.- D. The Cell Surface.- I. The Plasma Membrane.- 1. Water Movement.- 2. Ion Movement.- II. Folds and Glycocalyx.- E. Conclusions.- Acknowledgements.- References.- 4 - Transport in Giant Plant Cells II - Freshwater Cells.- A. Introduction.- B. Active Transport Processes.- I. General.- II. Cation Transport.- III. Active Proton Extrusion.- IV. Net Salt Accumulation.- 1. Transport at the Plasmalemma.- 2. Ion Transfer from Cytoplasm to Vacuole.- V. Bicarbonate Uptake.- VI. OH" Efflux.- C. Intercellular Transport.- D. Control of Ionic Composition.- E. Excitability of Characean Cells.- References.- 5 - Ion Transport and Turgor Pressure Regulation in Giant Algal Cells.- A. Introduction.- I. Origin and Functions of Turgor Pressure.- II. Historical Background.- III. Objectives and Scope of this Review.- IV. Functional Anatomy of a Plant Cell.- B. Basic Elements of Turgor Regulation.- I. Basic Concepts and Terminology.- II. Physical and Chemical Signals Related to Turgor Pressure.- III. Flux-Force Relationships Governing Fluid Movements in Walled Cells.- IV. Elements of a Turgor Regulation System.- V. Hypothetical Example of Turgor Regulation.- C. Experimental Methods of Measuring and Controlling Turgor Pressure.- I. Indirect Methods of Estimating Turgor.- II. Direct Methods of Measuring and Controlling Turgor Pressure.- D. Experimental Data on Osmotic Regulation.- I. Summary.- II. Valonia.- III. Codium.- IV. Halicystis.- V. Chaetomorpha.- VI. Nitella.- E. Cellular Transport Properties Affected by Turgor Pressure.- I. Ion Transport.- II. Protoplasm Conductance and the Vacuole Potential.- III. Water and Nonelectrolyte Permeability.- IV. Volumetric Elastic Modulus of the Cell Wall.- F. Location and Nature of the Turgor-Pressure Transducer.- I. Location of the Turgor Transducer.- II. Nature of the Turgor Transducer.- III. Separate Mechanism for Hypertonic and Hypotonic Regulation?.- G. Relations between Turgor Regulation and other Controlled Processes.- I. Regulation of Cytoplasmic Volume and Ionic Composition.- II. Turgor Regulation and Expansion Growth.- III. Developmental Aspects of Turgor Regulation.- IV. Inorganic Nutrient Uptake and Turgor Regulation.- H. Alternative Strategies for Controlling Turgor or Volume.- I. Relation between Volume Regulation and Turgor Regulation.- II. Regulation of Cell Volume by Contractile Vacuoles.- III. Regulation of Cell Volume or Turgor by Biochemical Interconversions.- IV. Indirect Regulation of Turgor by Regulation of Intracellular Solute Concentrations.- V. Regulation of Turgor or Volume by a Pump-Leak System.- J. Conclusions and Aims for Future Work.- Acknowledgements.- Note Added in Proof.- References.- 6 - Transport Across Amphibian Skin.- A. Introduction: The Amphibian Skin as Experimental Object.- B. Anatomical Problems.- C. The Outer Barrier.- I. Localization.- II. Cation Selectivity.- III. Cation Fluxes.- IV. Blocking Agents.- V. Regulation.- 1. Hormones.- 2. Chemical Agents.- 3. Sodium.- 4. Physical Factors.- D. The Transport Compartment.- E. The Internal Barrier.- I. Localization.- II. Cation Selectivity.- III. Cation Fluxes and Coupling Ratios.- F. The Potential Profile.- G. Chloride and Other Anions.- I. Passive Movements.- II. Active Transport.- H. Hydrogen Ion Secretion.- J. Aldosterone and Molting.- K. Conclusions.- References.- 7 - Transport Across Amphibian Urinary Bladder.- A. Introduction.- B. Structure as Related to Function.- C. Electrical Properties.- D. Membrane Selectivity.- E. Active Sodium Transport.- I. Sodium Entry at the Mucosal Border.- II. The Sodium Transport Pool.- III. Serosal Sodium Exit.- IV. The Effect of Vasopressin on Sodium Transport.- V. The Effect of Aldosterone on Sodium Transport.- F. Movement of Water and Other Nonelectrolytes: Effects of Vasopressing.- G. Effects of Other Hormones.- References.- 8 - Transport Across Insect Excretory Epithelia.- A. Introduction.- B. Malpighian Tubules.- I. Fluid Transport by Malpighian Tubules.- II. Ion Transport by Malpighian Tubules.- III. Coupling of Water Movements to Solute Movements.- IV. Evidence for a Common Cation Pump in Malpighian Tubules.- V. Transport of Chloride Ions.- VI. Transport of Mg and SO4 by Malpighian Tubules.- VII. Active Transport of Organic Compounds by Malpighian Tubules.- 1. Organic Anions.- 2. Organic Cations.- 3. Ouabain Excretion.- VIII. Resorptive Processes in Malpighian Tubules.- 1. KCl Resorption.- 2. Reabsorption of Sugars.- C. Transport Processes in the Hindgut.- I. Transport in the Anterior Hindgut.- 1. Absorption of KCl in the Hindgut Adult Pieris.- 2. Transport of NH+4 Ions by the Hindgut of Sarcophaga.- II. Transport Processes in the Insect Rectum.- 1. Recovery of Water.- 2. Absorption of Water Vapour from the Air.- a) Tenebrio molitor.- b) Thermobia domestica.- 3. Rectal Transport of Ions.- 4. Rectal Absorption of Aminoacids.- D. Transport Processes Important to Excretion in Other Epithelia.- I. Midgut.- II. Labial Glands.- III. Epidermis.- E. Concluding Remarks.- References.- 9 - Transport Across Insect Gut Epithelium.- A. Introduction.- I. Foregut.- II. Midgut.- III. Hindgut and Rectum.- B. Transport of Uncharged Molecules by the Insect Intestine.- I. Transport of Glucose.- II. Transport of Aminoacids.- III. Transport of Ions through the Midgut.- IV. Transport of Ions through the Hindgut of Sarcophaga.- 1. Sarcophaga.- 2. Millipede.- C. K-Pump of Cecropia.- I. Introduction.- II. Studies by Harvey and Nedergaard (1964).- III. Inhibitors.- IV. Oxygen Consumption and K Transport.- V. Effect of K Concentration on Bathing Solution on Potential Difference.- VI. K Flux and Isc.- VII. Mg Transport.- VIII. Competition Between the Alkali Metal Ions for the K-Pump.- IX. Competition of the Ions for Uptake by the Midgut.- X. Discussion.- D. Lag Time.- I. Pool Determination.- II. Cell Potential.- III. Cs Pool.- E. Uniformity of Gut.- I. K Concentration in Midgut Cells.- II. Exchange of K Between the Midgut Cell and the Outside K.- References.- 10 - Transport in Eye Epithelia: The Cornea and Crystalline Lens.- A. Introduction and Morphology.- B. The Cornea.- I. Structure of the Cornea.- II. Electrophysiology and Active Transport of Ions.- 1. The Corneal Epithelium.- a) Ionic Pumps.- b) Intracellular Recordings.- c) Sodium Dependence and Location of the Epithelial Pumps.- 2. The Transparency and Hydration of the Stroma.- a) Swelling.- b) Physical Basis for Corneal Transparency.- c) Diffusion of Ions and Molecules in the Stroma of the Cornea.- d) Concentration of Ions in the Stroma.- e) Permeability of Boundary Layers.- 3. The Corneal Endothelium.- 4. General Picture of Corneal Ion and Water Movements.- 5. Comparative Aspects.- a) Human Corneas.- b) The Cornea of Fishes.- 6. Action of Drugs and Hormones.- a) Epithelium.- b) Endothelium.- III. Transport of Nonelectrolytes.- 1. Aminoacids.- 2. Transport of Sugars.- C. The Crystalline Lens.- I. Structure of the Lens.- II. Basic Views on Transport Mechanisms in the Lens.- III. Electrophysiology of the Lens.- 1. Reexamination of the Pump and Leak Model.- 2. Short-Circuiting of the Isolated Lens.- 3. Extracellular Space in the Lens.- 4. Ionic Fluxes.- 5. Interfibrillar Low-Resistance Pathways.- IV. Transport of Nonelectrolytes.- V. Cataract Formation.- Acknowledgements.- References.- 11 - Transport in Eye Epithelia: Ciliary Epithelium and Retina Pigment Epithelium.- A. Introduction.- B. Ciliary Epithelium and Outflow Channels.- I. Structure of the Ciliary Epithelium and Outflow Channels for the Aqueous Humor.- II. Basic Concepts of Fluid Formation and Outflow.- III. Electrophysiology of the Ciliary Epithelium.- IV. Ultrafiltration Versus Secretion.- V. New Theories for Aqueous Humor Outflow Mechanisms.- VI. Comparative Aspects.- C. Retina Pigment Epithelium.- I. Structure and Relationship with the Neural Retina and Choroid.- II. The Retinal Pigment Epithelium as a Diffusion Barrier and Site of Transport.- Acknowledgements.- References.- 12 - Ion Transport Across the Choroid Plexus.- A. Introduction.- B. The Experimental Approach.- C. Ion Fluxes Across the Epithelium.- I. The Mode of Action of Ouabain.- II. The Site of Ouabain Binding.- D. Na-K-ATPase and Secretion.- E. The Intracellular Na and K Concentrations.- F. Potassium Transport Across the Apical Membrane.- I. Pharmacological Aspects.- II. The Role of HCO?3.- G. Na and CI Fluxes Across the Apical Membrane.- H. Passive Permeation.- J. A Model for Ion Transport.- Acknowledgements.- References.- 13 - The Sweat Glands.- A. Introduction.- I. The Eccrine Glands of the General Body Surface.- II. The Eccrine Glands on the Palms and the Soles.- III. The Apocrine Glands of the Axillary, Genital, Perineal, and Perianal Regions.- B. The Morphology of the Sweat Glands.- I. The Epithelium of the Eccrine Secretory Coil.- II. The Epithelium of the Eccrine Duct.- III. The Myoepithelium.- IV. The Apocrine Glands.- C. The Vascularization of the Sweat Glands.- D. Innervation of the Sweat Glands.- I. Innervation of the Duct Epithelium.- II. Innervation of the Secretory Coil.- E. Number of Sweat Glands.- F. Maximum Rate of Secretion.- G. Rate of Secretion from Individual Glands.- I. Glandular Intermittency.- II. Variation in Secretory Rate per Gland.- III. Variation in Functional Capacity of Individual Sweat Glands Within and Between Skin Areas.- H. Ionic Composition of Sweat in Relation to Secretory Rate.- I. Methodological Problems.- 1. Sample Contamination.- 2. Rate-Independent Variables.- 3. Rate per Gland.- 4. Dead Space.- II. Sodium.- 1. Relation Between Sodium Concentration and Secretory Rate in Sweat Harvested from a Smaller or Larger Skin Area.- 2. Relation Between Sodium Concentration and Secretory Rate in Sweat Harvested from Single Sweat Glands.- III. Potassium.- IV. The Potassium Transient.- V. Anions.- J. Mechnism of Secretion.- I. Direct Observation of the Composition of the Primary Secretion.- 1. Microcryoscopic Methods.- 2. Micropuncture of the Secretory Coil.- 3. The Isolated Secretory Coil.- II. Direct Observation of the Modification of the Primary Secretion in the Duct.- III. The Mechanism of Formation of the Primary Secretion.- IV. The Mechanism of Ductal Sodium Reabsorption.- K. The Metabolism of the Sweat Glands.- L. Species Differences in Eccrine Sweat Gland Function.- I. The Eccrine Sweat Gland of the Monkey's Palm.- II. The Eccrine Sweat Gland of the Cat's Paw.- III. The Eccrine Sweat Gland of the Rat's Paw.- References.- 14 - The Lacrimal Gland.- A. Introduction.- B. Tears.- I. The Conjunctival Glands.- 1. The Mucin Secretors.- 2. The Lacrimal Secretors.- 3. The Oil Secretors.- II. The Lacrimal Gland (the "reflex secretor").- III. The Relative Volume Rate of Secretion from the Conjunctival Glands and the Lacrimal Gland.- IV. Ionic Composition of Tears and Lacrimal Gland Secretion.- C. Structure of the Lacrimal Gland.- D. Innervation of the Lacrimal Gland.- I. Histological Studies.- II. Physiological and Neurophysiological Studies.- 1. Parasympathetic Stimulation.- 2. Sympathetic Stimulation.- E. Ionic Composition of Lacrimal Gland Secretion in Relation to Secretory Rate.- I. Tears.- II. Uncontaminated Lacrimal Gland Secretion.- F. Potassium Transient.- G. Mechanism of Secretion by the Lacrimal Gland.- I. Primary Secretion of the Lacrimal Gland.- II. Modification of the Primary Secretion in the Lacrimal Gland Ducts.- III. Glandular Blood Flow.- IV. Mechanism of Formation of the Primary Secretion.- 1. The Resting Potential over the Inner Acinar Cell Membrane.- 2. The Secretory Potential over the Inner Acinar Cell Membrane.- 3. The Secretory Potential over the Outer Acinar Cell Membrane.- References.
