The recogmuon recogmtIon of the microcirculation as an ideal interdisciplinary meeting place for the life sciences is really a postwar phenomenon. The European and the American Societies more than any other organizations launched the idea, and the success of the European Society's International Meetings gave impetus to a growth of interest from a handful of specialists to the wide interdisciplinary study which microcirculation now represents. The meeting held in Canada in June 1975 was, however, the first truly international meeting devoted to the microcirculation. It, too, was a success from every point of view, and the exchange of knowledge and new ideas was rewarding. It is our present hope that the tradition of European meetings with their characteristic European flavor will continue, but larded by larger, international congresses conceived on a worldwide basis. For the present conference we were fortunate in the presence of Dr. B. Zweifach. He was once referred to as the "father of the microcircula- tion." This claim, unfortunately, I cannot accept. That honor probably belongs to Harvey, who by one of the most brilliant strokes of inductive reasoning in medical history inferred the existence of capillaries though he could not see them. Ben Zweifach's role was rather that of the midwife, presiding at the birth rather than the conception. The baby he delivered long years ago has since thriven lustily and its growth is in no small measure due to the continuing zeal of Zweifach and his associates.

Table of Contents:
I. Blood and Blood Vessel Interaction.- 1. Blood Rheology Interpreted through the Flow Properties of the Red Cell.- 1.1. Macroscopic Rheology and Tube Flow of Human Blood.- 1.2. Red Cell Interactions in Low Flow States.- 1.3. Rheology of Red Blood Cell Membrane.- 1.4. Pressure-Flow Relationships in the in Vivo Microcirculation.- 2. Methods for the Investigation of the Microcirculation.- 2.1. Noninvasive Measurement of Compliance of Small Arteries.- 2.3. A Method of Determining Resistances from Pressure-Flow Measurements with Microvascular Occlusions.- 2.4. Image Degradation in Magnification Radiology by Phase Shift.- 2.5. A New Low-Density, Nonaggregating Microsphere for Microcirculation Research.- 2.6. Development of an Index for Evaluating the Response of the Microvasculature in C3H Mice to Various Vasoactive Drugs.- 2.7. A Microscope Laser Doppler Anemometry (LDA) System for Measurement of Flow Velocity and Velocity Profiles in Vivo in the Vessels of the Microvascular System.- 2.8. A Video System for Measuring the Blood Flow Velocity in Microvessels.- 2.9. New Methods of Measuring the Different Rheological Parameters in Blood.- 2.10. Internal Tissue Heat during in Vivo Transillumination with Fused Quartz and Borosilicate Glass Rods.- 3. Red Cell Interactions with the Microcirculation.- 3.1 Red Blood Cell Velocity Profiles in Arterioles and Venules of the Rabbit Omentum.- 3.2 Analysis of Red Blood Cell Velocity Distribution in Human Nailfold Capillaries.- 3.3 In Vivo Study of "Apparent Viscosity" and Vessel Wall Shear Stress in Cat Mesentery.- 3.4. Flow Velocities of Red Blood Cells and Their Suspending Medium Measured in Glass Capillaries Using the Photometric Dual-Slit Method.- 3.5. A New On-Line Method of Measuring High Flow Speeds in Microscopic Vessels by a Dual Video Camera Technique.- 3.6. Blood Cells in an Annular Vortex.- 3.7. Geometry of the Fetal Erythrocyte and Its Relation to Osmotic Fragility.- 3.8. Electrochemical and Mechanical Factors in Red Cell Interactions.- 3.9. Role of the Erythrocyte Surface Charge in the Microcirculation.- 3.10. Velocity-Dependent Resistance Behavior of Erythrocytes in Capillary Pores and Membrane Elasticity.- 3.11. Effects of Altered Red Cell Deformability on Capillary Flow Resistance.- 3.12. Effect of Heat-Traumatized Blood on Microcirculatory Dynamics.- 3.13. Effect of Heat-Induced Spherocytes on Intrahepatic Microcirculation.- 3.14. Locomotion and Chemotaxis of Human Neutrophils.- 3.15. Leukocyte Adhesiveness as Influenced by Blood Velocity.- 3.16. Erythrocyte and Platelet Geometry: Comparative Quantitative Estimates by Static Microscopic and Rheo Optical Determinations.- 3.17. Erythrocyte Sedimentation of Human Blood at Varying Shear Rates.- 3.18. Erythrocyte Sedimentation Rate and "a Sedimentimeter".- 3.19. Osmotic Fragility Curves as Frequency Distributions.- 3.20. Psychosomatic Pain and Elevation of Blood Viscosity Factors.- 3.21. Blood Viscosity Factors in Diagnostic and Preventive Medicine.- 3.22. Rheological Properties of Sickled Red Cells in the Microcirculation.- 3.23. Some Effects of Tube Diameter on Oscillatory Blood Flow.- 4. Blood Vessel Structure.- 4.1. An Intracellular Tubular System in Capillary Endothelium.- 4.2. Observations of Pulmonary Capillary Endothelial Junctions Studied by the Freeze-Fracture/Etch Technique.- 4.3. On the Fine Structure of the Arteriovenous Anastomoses of the Rabbit Ear.- 4.4. Scanning Electron Microscopic Evaluation of Rat Femoral Artery Endothelium Following Microvascular Surgery.- 4.5. On the Organ Specificity of Microvessels: Heterogeneity of Arteriolar Metabolism.- 5. Microcirculatory Flow Patterns.- 5.1. The Natural History of Microcirculation.- 5.2. Increased Capillary Flow Rate of Erythrocytes in Hyperosmolar Human Blood by the Addition of Pentoxifylline.- 5.3. Measurement of Arteriovenous Circulation Time and Volume Flow in the Human Retin.- 5.4. Microcirculation of the Terminal Gill Lamellae in the Freshwater Goldfish (Carassius auratus) and the Marine Gobie (Lythrypnus dalli).- 5.5. Flow Patterns in the Capillary Bed of Rat Skeletal Muscle at Rest and after Repetitive Tetanic Stimulation.- 5.6. Transcapillary Pressure Gradients and Coefficients during Isotonic Mannitol Loads: Evidence for Capillary Intermittency.- Segmental Resistances in the Microcirculation of the Mesentery and Omentum.- 6. Formed Elements of the Blood Platelets, and Thrombosis.- 6.1. Platelets in Response to the Injury in the Microcirculation- A Review.- 6.2. Double Labeling of Platelets with 5 1 Cr and [14C]Serotonin.- 6.3. Inhibition of Platelet Function by Angiographic Contrast Media.- 6.4. Electronic Particle Size Measurement of Platelet Aggregates.- 6.5. Videomicroscopy and Videodensitometry of Platelet Aggregation under Controlled Conditions of Blood Flow and ADP Convective Diffusion.- 6.6. Effects of Agar on Platelet Aggregation.- 6.7. Effects of pH and PC02 on ADP-Induced Platelet Sphering and Aggregation for Human and Rabbit Citrated Platelet-Rich Plasma.- 6.8. Effect of a New Potent Inhibitor of Platelet Aggregation (BL-3459) on Experimental Thrombosis.- 6.9. Hematological Effects of a Splenic Extract.- 6.10. Inhibition of ADP-Induced Platelet Aggregation by Canine Spleen Alkaline Phosphatase.- 6.11. Effect of Diflunisal, a Novel Salicylate, on Platelet Function and Blood Coagulation.- 6.12. Polyphloretin Phosphate, an Inhibitor of Platelet Function.- 6.13. Platelet Aggregation and Particulate Microembolization during Cardiac Operations.- 6.14. Growth Patterns of Platelet Thrombi and Their Relationship to Microemboli.- 6.15. Effect of Hormonal Contraceptives on Electrically Induced Thrombosis Times in Rats.- 6.16. Interaction between Platelet Thrombi and the Vessel Wall.- Platelet and Fibrinogen Preservation in Intraoperative Autotransfusion.- 6.18. Effect of Gliclazide on Irradiation-Induced Experimental Atheromatosis.- 6.19. A Diagnostic Sign in the Small Blood Vessels of the Conjunctiva in Arteriosclerosis.- 6.20. Ventilatory Dysfunction after Long-Lasting Intravascular Platelet Aggregation.- 6.21. Studies on Platelet and Red Cell Survival after Cardiopulmonary Bypass (CPB) without Blood Filter.- 6.22. Osmotic Fragilities and the Kalmedic Fragiligraph Model D-3.- 7. Lymphatics.- 7.1. Electron Microscopic Studies of the Lymphatic Endothelium in Lymphangiectasia of the Small Intestine.- 7.2. Microcirculation of the Human Lymph Node.- 7.3. Quantitation of Blood Flow to and Lymph Output from Single Lymph Nodes.- 7.4. Flow of Albumin through Renal Lymph: The Total Clearance.- 7.5. Contributions to Regional Tissue Lymph by the Local Lymph Node in Sheep.- 7.6. Effects of Chemical and Physical Conditions on the Flow Rate of Intestinal Lymphatics.- 7.7. Lymph Flow Augmentation Secondary to Rises in Serum Calcium.- 7.8. Transport of Air via Lymph Vessels in Experimentally Induced Emphysema.- 8. Neurohumoral Control of Blood Vessels.- 8.1. Integrated Response of the Microvasculature to Stimulation of the CNS in the Rat.- 8.2. Comparative Studies on Adrenergic Receptors in Different Rat Blood Vessels.- 8.3. Adrenergic Innervation of the Blood Vessels of the Spinal Cord of the Cat.- 8.4. Effect of CO2 on the ?-Adrenergic Receptor: A Control Mechanism for Tissue Blood Flow.- 8.5. Effects of a and ? Blockade on Oxygen Supply to Rat Brain and Muscle.- 8.6. Evidence for Increased ?-Adrenergic Receptor Function in Isolated Perfused Carotid Artery from Cold- Acclimated Rabbits.- 8.7. Catecholamines in Low Flow States.- 8.8. Effect of Steroids on Human Venous Smooth Muscle in Vivo and in Vitro.- 8.9. Direct Contractile and Metabolic Actions of Nitroglycerine on the Heart.- II. Blood Flow in Special Tissues.- 9. Pulmonary Circulation.- 9.1. Biomicroscopic Investigations on the Connection between the Capillary Bed and the Larger Vessels of the Lungs of Some Reptiles.- 9.2. Pulmonary Capillary Filtration Coefficient and Permeability to HRP in Dogs.- 9.3. Weight vs. Electrode Detection of Outflow Response of Isolated Perfused Dog Lung to Osmotic Solutes.- 9.4. Pulmonary Extraction of 5-Hydroxytryptamine: Antagonism by Imipramine ill the Intact Anima.- 9.5. Pulmonary Microcirculation during Lethal Hypovolemia in the Cat.- 10. Myocardial Blood Flow.- 10.1. Microcirculation in the Ventricle of the Dog and Turtle.- 10.2. Temporal Heterogeneity of Myocardial Perfusion.- 10.3. A New Model for Assessing Myocardial Function.- 10.4. Washout and Washin Behavior of the Myocardial Extracellular Space: Significance for Evaluation of Capillary Permeability and Interstitial Space Concentrations of Metabolites.- 10.5.. Changes in Coronary Vessels Induced by Repeated Hypothalamic Stimulation.- 10.6. Microangiographic Reevaluation of the Human Intramyocardial Vasculature.- 10.7. Predictive Value of Myocardial Scanning for Coronary Artery Bypass Surgery.- 10.8. Myocardial Perfusion Defects in Patients with Valvular Heart Disease.- 10.9. Myocardial Perfusion Abnormalities in Patients with Cardiomyopathy.- 10.10. Fluorescence Microscopic Demonstration of Localized Myocardial Ischemia.- 10.11. Oxygen Utilization and Coronary Vascular Reserve in the Ischemic Myocardium Following Acute Coronary Occlusion in the Dog.- 10.12. Reduction of Myocardial Infarct Volume by Methylprednisolone.- 10.13. Pathological Anatomy of the Subendocardial Vasculature after Anoxic Cardiac Arrest.- 10.14. Metabolic Response of the Heart to Ischemic Arrest during Cardiac Surgery: Assessment by Means of Intramyocardial Carbon Dioxide Tension.- 10.15. Prevention of "Stone Heart" after Anoxic Cardiac Arrest.- 10.16. Effect of Aprotinin on Levels of Adenine Nucleotides and Nucleosides in Postischemic Myocardium in Dogs.- 11. The Splanchnic Circulation.- 11.1. Microvascular Pressures in Innervated Rat Intestinal Muscle and Mucosa.- 11.2. Microsphere Distribution in Revascularized Intestine.- 11.3. Microcirculation from the Villus to the Liver.- 11.4. Biomicroscopic Studies of Microcirculation of the Rat Intestine.- 11.5. Filtration Coefficients of Single Capillaries in Rat Intestinal Muscle.- 11.6. Role of Collagenase in Capillarization of Hepatic Sinusoids.- 11.7. Effect of Diminished P50 on Intrahepatic Oxygen Tension as Measured in Bile.- 11.8. Phenomenon of Intrahepatic Microcirculatory Redistribution.- 11.9. A Flow Model of the Liver and the Microcirculatory Hepatic Unit.- 11.10. The Isolated Perfused Liver as a Model for the Study of Disseminated Intravascular Coagulation. I. Effects of Trasylol, Heparin, and Acetylsalicylic Acid.- 11.11. Effects of Acute Hemorrhage and Carotid Artery Occlusion on Blood Flow and Its Distribution in the Wall of the Gastrointestinal Tract.- 11.12. Effects of Arterial Pressure Variation on Microvascular Pressure Distribution in the Mesentery during Intravenous Infusion of Norepinephrine.- 11.13. Mechanism of Escape from Norepinephrine Vasoconstriction in the Intestinal Circulation.- 11.14. In Vivo Study of the Effects of Acetaminophen(Paracetamol) on the Hepatic Mic~ocirculation.- 11.15. In Vivo and Electron Microscopic Study of the Splenic Microvascular System.- 11.16. Experimental and Theoretical Investigations on Intrasplenic Microcirculation in Rats.- 11.17. Neural Influences in the Humoral Regulation of the Splenic Microvasculature.- 11.18. The pH of Splenic Microcirculation.- 11.19. Specific Erythropoietin-Related Changes in the Splenic Microcirculation during Hypoxic and Posthypoxic Polycythemia: Comparison with Other Organs.- 12. Blood Flow in Skeletal Muscle.- 12.1. Microcirculation in Skeletal Muscle: Geometry of the Capillary Vascular Network.- 12.2. Regions of Preferential Blood Flow in Skeletal Muscle.- 12.3. Distribution of Blood Flow in Microcirculation in Cat Tenuissimus Muscle.- 12.4. Apparent Distribution of Capillary and Shunt Flow in Canine Skeletal Muscle.- 12.5. The Microvascular Bed and Capillary Surface Area in Rat Extensor Hallucis Proprius Muscle.- 12.6. Kinetics of Red Cell and Plasma Washout from the Vascular Bed of Skeletal Muscle.- 12.7. Blood Oxygen Saturation Determination in Frozen Dog Gracilis Muscle.- 12.8. Functional Arteriolar Vasodilatation in Striated Muscle.- 12.9. Blood Flow Changes Due to Compression in Contracting Muscles.- 12.10. Changes in the Capillary Density and Reactivity of the Vascular Bed in Chronically Stimulated Fast Muscles.- 12.11. Skeletal Muscle Vascular Volume Changes with Increased Venous Pressure.- 12.12. Flow Improvement in the Vasodilated Skeletal Muscle of the Dog by Slow Defibrinogenation with Arvin.- 13. Microcirculation in Other Tissues.- 13.1. Quantitative Studies of Brain Microcirculation Using Quasilinearization Techniques.- 13.2. Microangiography and Tryptan Blue Fluorescence Study of Cardiac-Arrested Dog Brain.- 13.3. Pharmacological Control of O2 Autoregulation in Brain Tissue.- 13.4. "Migraine"-Studies on Intravital Microcirculation: Synergism of the Action between Serotonin and Bradykinin on the Encephalic Circulation System.- 13.5. Oxygen Supply to the Spinal Cord and Its Autoregulation.- 13.6. Regional Changes in Pial Blood Supply Induced by Hypothalamic Stimulation.- 13.7. Influence of Aminophylline on the Cerebral Blood Circulation and CSF Pressure.- 13.8. Electrocorticographic and Pial Microvascular .Hemodynamic Correlations during Pentylenetetrazol- and Enflurane- Induced Seizures in the Cat.- 13.9. Regional Blood Flow in Normal Skin and the Pedicle Skin Thp.- 13.10. Microvasculature in Open Cremaster.- 13.11. Childhood Asthma and Peptic Ulcer: Studies of the Lip Capilmries.- 13.12. Effects of Perfusion Pressure on Focal Ischemia in the Retina: Experimental and Clinical Studies.