Endothelial Cells In Health And Disease

Although blood capillaries were first observed through a flea-lens microscope by Malpighi in 1661,200 more years elapsed before the cellular nature of the vessel wall was conclusively demonstrated. Beginning with the middle of the 19th cen tury, our knowledge of the histological organization of blood vessels has steadily increased. However, the endothelium, which for a long time was considered to be just an inert barrier lining, had been barely explored until three decades ago. Since then, there has been an upsurge of interest in the fine structure and function of endothelial cells. Intense in vivo and in vitro investigations have revealed that the endothelial cell is a key element in a wide variety of normal activities and diseases. A large number of investigators and laboratories have been attracted to endothelial cell research, thus supporting the expansion of the continuously grow ing and diversifying field of endotheliology. The number of articles published annually on this subject has increased from a few score at the beginning of the 1970s to more than a thousand in recent years, and an increasing number of journals, books, societies, and symposia focused primarily on the vascular en dothelium have marked the last decade.

This reference serves as the first source to gather current data from endothelial cell biologists in various disciplines to summarize recent progress in the field-providing a complete understanding of the endothelium in health and disease and demonstrating its potential as a therapeutic target.

The endothelium, a monolayer of endothelial cells, constitutes the inner cellular lining of the blood vessels (arteries, veins and capillaries) and the lymphatic system, and therefore is in direct contact with the blood/lymph and the circulating cells. The endothelium is a major player in the control of blood fluidity, platelet aggregation and vascular tone, a major actor in the regulation of immunology, inflammation and angiogenesis, and an important metabolizing and an endocrine organ. Endothelial cells controls vascular tone, and thereby blood flow, by synthesizing and releasing relaxing and contracting factors such as nitric oxide, metabolites of arachidonic acid via the cyclooxygenases, lipoxygenases and cytochrome P450 pathways, various peptides (endothelin, urotensin, CNP, adrenomedullin, etc.), adenosine, purines, reactive oxygen species and so on. Additionally, endothelial ectoenzymes are required steps in the generation of vasoactive hormones such as angiotensin II. An endothelial dysfunction linked to an imbalance in the synthesis and/or the release of these various endothelial factors may explain the initiation of cardiovascular pathologies (from hypertension to atherosclerosis) or their development and perpetuation. Table of Contents: Introduction / Multiple Functions of the Endothelial Cells / Calcium Signaling in Vascular Cells and Cell-to-Cell Communications / Endothelium-Dependent Regulation of Vascular Tone / Conclusion / References

In recent years there has been rapid progress in research on vascular endothelium. This has led to significant advances in our understanding of the structure and function of vascular endothelium in health and disease, including such aspects as the permeability of endothelium in relation to its ultrastructural correlates, theoretical basis, regulatory factors, and role in atherogenesis; the interaction between endothelium and blood cells; the endothelial release and processing of a number of important physiological agents, such as eicosanoids, hemostatic factors, and histamine; the cell biology of endothelium with respect to the cytoskeletal apparatus, cell activation, and cell locomotion; and the role of endothelium in microcirculatory regulation in normal and pathophysiological circumstances. A Symposium on "Vascular Endothelium in Health and Disease" was held on August 5-6, 1987, at the Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China, following the 4th World Congress for Microcirculation in Japan. Experts working on various aspects of vascular endothelium came from allover the world to participate in this two-day Symposium and gave excellent presentations. This volume, embodying the proceedings of that Symposium, is a collection of the papers given by the speakers with, in many cases, further updating and new information added subsequent to the Symposium. The Institute of Biomedical Sciences (IBMS), the site of this Symposium, is a newlJl established research institution, which has vascular endothelium as one of its areas of research emphasis.

Vascular endothelial plays a significant role in regulating blood flow, and endothelial cells (EC) have highly active metabolic functions. This volume focuses on Vascular Endothelium, NO and Hypertension and is a continuum of the volumes on Mechanobiology of Cartilage and Chondrocyte.

It is only during the last decade that the functions of sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, pit cells and other intrahepatic lymphocytes have been better understood. The development of methods for isolation and co-culturing various types of liver cells has established that they communicate and cooperate via secretion of various intercellular mediators. This monograph summarizes multiple data that suggest the important role of cellular cross-talk for the functions of both normal and diseased liver. Special features of the book include concise presentation of the majority of detailed data in 19 tables. Original schemes allow for the clear illustration of complicated intercellular relationships. This is the first ever presentation of the newly emerging field of liver biology, which is important for hepatic function in health and disease and opens new avenues for therapeutic interventions.