Platelet Heterogeneity

1 Platelet Density, Heterogeneity and Platelet Ageing.- Experimental Models Used to Examine the Significance of Platelet Heterogeneity.- Potential Problems Associated with Various Experimental Models.- Ultrastructural Studies and Platelet Heterogeneity.- Density-Dependent Platelet Properties and Platelet Heterogeneity.- Kinetic Models to Examine the Relationship Between Platelet Density and Age.- Is Heterogeneity of Density-Dependent Platelet Properties Significant?.- Contributions of Events During Thrombopoiesis to Platelet Heterogeneity.- Conclusions.- References.- Technical Questions.- 2 The Biology of Platelet Volume Heterogeneity.- Characteristics of Size-Dependent Platelet Subpopulations.- Relationship of Platelet Size to Platelet Age.- The Relationship of the Mean Platelet Volume to the Platelet Count.- Summary.- References.- Technical Questions.- 3 Is Platelet Heterogeneity Due to Ageing or Thrombopoiesis?.- Method of Separation of Platelets on Stractan Density Gradients.- Types of Experiments.- Recovery of Ability of Platelets to Synthesize Thromboxane After Aspirin Administration.- Conclusions About the Relation Between Density and Survival of Rabbit Platelets.- Do Discontinuous Gradients Introduce Artefacts?.- Differences Between Most Dense and Least Dense Platelet Subpopulations.- Effect of Aggregating and Release-Inducing Agents on Platelet Density.- Effect on Density of Raising the Concentration of Cyclic AMP in Rabbit Platelets.- Changes in Density In Vivo.- Conclusions.- References.- Technical Questions.- Discussion (Chapters 1–3).- 4 Origins and Significance of Platelet Heterogeneity in a Non-human Primate Model.- Platelet Density.- Characterization of Young Platelets.- Chronic Thrombocytopenia.- Acquired Platelet Alterations.- Conclusions.-References.- 5 Platelet Formation, Platelet Density and Platelet Ageing.- The Proplatelet Theory of Platelet Formation.- Platelet Density Heterogeneity and Platelet Ageing.- Conclusions.- References.- 6 Characterization of Platelets and Megakaryocytes of the Wistar Furth Rat: An Animal Model with Inherently Large Mean Platelet Volume.- Materials and Methods.- Results.- Discussion.- References.- Technical Questions.- 7 The Circulating Megakaryocyte, Platelet Volume Heterogeneity and Thrombopoiesis.- The Concept of Bone Marrow Thrombopoiesis: How Did It Start?.- The Megakaryocyte Demarcation Membrane System and Platelet Territories.- Diapedesis and Sinusoidal Megakaryocytes.- Circulating Megakaryocytes.- Pulmonary Megakaryocytes.- Platelet Volume Heterogeneity.- Pulmonary Thrombopoiesis: A Simple Mechanism.- Conclusions.- References.- 8 The Genesis of Platelet Volume and Density Distributions.- Platelet Size Distributions From Normal Subjects Approximate Log-normality.- Circulating Platelet Populations of Widely Different Age Distributions Approximate Log-normality.- Platelet Volume Can Be Regulated.- Platelet Volume Is Inversely Correlated to Platelet Count.- Platelet Volume and Density Are Partially Correlated.- Platelet Function Is Linked to Platelet Size and Density.- Megakaryocyte Ploidy Heterogeneity Cannot Explain Log-normality.- Fragmentation and Growth of Megakaryocyte Cytoplasm Are Major Determinants of Platelet Size.- References.- Discussion (Chapters 7 and 8).- 9 Platelet Heterogeneity in Vascular Disease.- The Origin of Platelet Heterogeneity.- Normal Physiological Response to Change in Platelet Destruction.- The Control of Platelet Production.- Platelet Volume in Myocardial Infarction.- The Bleeding Time in Myocardial Infarction.- Platelet Volume and Megakaryocytes in Animal Models of Vascular Disease.- Conclusions.- References.- Technical Questions.- 10 The Heterogeneity of Platelets.- References.- Technical Questions.- General Discussion.- 11 Summing Up: Platelet Heterogeneity: Biology and Pathology.- Bone Marrow and Thrombopoiesis.- References.- Discussion.- 12 Chairman’s Commentary.- Technical Questions.- Basic Questions.