The aim of this symposium was to provide a framework for fruitful discussion on intestinal transport, not only for advanced scientists but also for younger people starting in this field of research. Invited lectures, communications and poster presentations were focused on four central themes, all treating the prop­ erties of the sole intestinal epithelium, deliberately leaving aside problems dealing with more integrative functions of the whole intestine. The importance of motility or blood circulation, for instance, is certainly capital in the overall intestinal function, but these aspects by themselves deserve another meeting. This volume has compiled the manuscripts of the invited lectures which sub­ stantially comprised the four sessions of the Symposium. Part 1 is designed to emphasize actual knowledge of the transport of water, inorganic as well as organic ions and molecules across the isolated intestinal epithelium. An enormous wave of investigations has emerged from studies per­ formed with "Ussing chambers", which roused interest in studies on absorption mechanisms and subsequently on secretory processes. This has triggered off a trend to research on isolated cells as absorption and secretion are the main func­ tion of the different cell types constituting the intestinal epithelium. In this first session not only the importance of the parallel arrangement of these different cellular entities is stressed, but also the role played by the paracellular route.

Inhalt

Introductory Survey.- Contributions and Stimulus to Intestinal Transport Studies.- 1. From the Whole Epithelium to Isolated Cells.- Routes of Water Flow Across the Intestine and Their Relationship to Isotonic Transport.- Absorption of Inorganic Ions and Short-Chain Fatty Acids in the Colon of Mammals.- Cellular Aspects of Amino-Acid Transport.- Statistical Analysis of Solute Influx Kinetics.- Intestinal Secretion of Organic Ions.- Coupling Stoichiometry and the Energetic Adequacy Question.- Several Compartments Involved in Intestinal Transport.- 2. Brush Border and Basolateral Membranes.- Mechanisms of Sodium Transport Across Brush Border and Basolateral Membranes.- Transport of Inorganic Anions Across the Small Intestinal Brush Border Membrane.- Mechanisms of Sugar Transport Across the Intestinal Brush Border Membrane.- Mechanism of Active Calcium Transport in Basolateral Plasma Membranes of Rat Small Intestinal Epithelium.- The small Intestinal Na+, D-Glucose Cotransporter: a Likely Model.- Protein-Lipid Interactions and Lipid Dynamics in Rat Enterocyte Plasma Membranes.- 3. Regulation of Intestinal Transport.- Role of Cell Sodium in Regulation of Transepithelial Sodium Transport.- Calcium Regulation of Intestinal Na and CI Transport in Rabbit Ileum.- Role of Calcium and Cyclic Nucleotides in the Regulation of Intestinal Ion Transport.- Neuro Hormonal Control of Intestinal Transport.- Hormone Regulation of Intestinal Calcium and Phosphate Transport: Effects of Vitamin D, Parathyroid Hormone (PTH) and Calcitonine (CT).- 4. Comparative Aspects of Intestinal Transport.- Comparative Aspects of Amino Acid Transport in Guinea Pig, Rabbit and Rat Small Intestine.- Temporal Adaptation and Hormonal Regulation of Sodium Transport in the Avian Intestine.- Effect of Galactose on Intracellular Potential and Sodium Activity in Urodele Small Intestine. Evidence for Basolateral Electrogenic Sodium Transport.- Transport of Ions and Organic Molecules in the Midgut of some Lepidopteran Larvae.- Electrical Phenomena in Fish Intestine.- Intestinal Transport and Osmoregulation in Fishes.- Biochemical Adaptation of Trout Intestine Related to Its Ion Transport Properties. Influence of Dietary Salt and Fatty Acids, and Environmental Salinity.