This unique volume covers the physiological responses and adaptations to hypoxia, the deficiency or absence of oxygen. These responses may occur at any level of an organism, from the mitochondria to organ systems, to the whole animal. The book emphasizes the molecular and cellular mechanisms, then integrates these responses in the context of organ and systems physiology, providing a useful reference for physiologists and other blood biologists, as well as pulmonary physicians

​ Over the last decade the science and medicine of high altitude and hypoxia adaptation has seen great advances. High Altitude: Human Adaptation to Hypoxia addresses the challenges in dealing with the changes in human physiology and the particular medical conditions that arise from exposure to high altitude. In-depth and comprehensive chapters cover both the basic science and the clinical consequences of exposure to high altitude. Genetic, cellular, organ and whole body system responses to high altitudes are covered and chapters discuss these effects on a wide range of diseases. Expert authors provide insight into the care of patients with pre-existing medical conditions that fail in some cases to adapt as well as offer insights into how high altitude research can help critically ill patients. High Altitude: Human Adaptation to Hypoxia is an important new volume that offers a window into greater understanding and more successful treatment of hypoxic human diseases.

The appearance of photosynthetic organisms about 3 billion years ago increased the partial pressure of oxygen (PO2) in the atmosphere and enabled the evolution of organisms that use glucose and oxygen to produce ATP by oxidative phosphorylation. Hypoxia is commonly defined as the reduced availability of oxygen in the tissues produced by different causes, which include reduction of atmospheric PO2 as in high altitude, and secondary to pathological conditions such as sleep breathing and pulmonary disorders, anemia, and cardiovascular alterations leading to inadequate transport, delivery, and exchange of oxygen between capillaries and cells. Nowadays, it has been shown that hypoxia plays an important role in the genesis of several human pathologies including cardiovascular, renal, myocardial and cerebral diseases in fetal, young and adult life. Several mechanisms have evolved to maintain oxygen homeostasis. Certainly, all cells respond and adapt to hypoxia, but only a few of them can detect hypoxia and initiate a cascade of signals intended to produce a functional systemic response. In mammals, oxygen detection mechanisms have been extensively studied in erythropoietin-producing cells, chromaffin cells, bulbar and cortical neurons, pulmonary neuroepithelial cells, smooth muscle cells of pulmonary arteries, and chemoreceptor cells. While the precise mechanism underpinning oxygen, sensing is not completely known several molecular entities have been proposed as possible oxygen sensors (i.e. Hem proteins, ion channels, NADPH oxidase, mitochondrial cytochrome oxidase). Remarkably, cellular adaptation to hypoxia is mediated by the master oxygen-sensitive transcription factor, hypoxia-inducible factor-1, which can induce up-regulation of different genes to cope the cellular effects related to a decrease in oxygen levels. Short-term responses to hypoxia included mainly chemoreceptor-mediated reflex ventilatory and hemodynamic adaptations to manage the low oxygen concentration while more prolonged exposures to hypoxia can elicit more sustained physiological responses including switch from aerobic to anaerobic metabolism, vascularization, and enhancement of blood O2 carrying capacity. The focus of this research topic is to provide an up-to-date vision on the current knowledge on oxygen sensing mechanism, physiological responses to acute or chronic hypoxia and cellular/tissue/organ adaptations to hypoxic environment.

Adaptation to altitude hypoxia is characterized by a variety offunctional changes which collectively facilitate oxygen trans port from the ambient medium to the cells of the body. All of these changes can be seen at one time or another in the course of hypoxic exposure. Yet, as already stressed (Hannon and Vogel, 1977), an examination of the literature gives only a sketchy and often conflicting picture of the exact nature of these changes and how they interact as a function of exposure duration. This is partly because of the limited number of variables explored in a given study, but it is also attributable to differences in experimental design, differences among species in susceptibility to hypoxia, nonstandardized experimental conditions, lack of proper control of physical (e. g. , temperature) and physiological variables (e. g. , body mass), failure to take measurements at key periods of exposure, and gaps in knowledge about some fundamental mechanisms. Furthermore the available data on animals native to high altitude are meager and/or inconclusive. Extensive further work under well-controlled experimental conditions is required before a detailed picture can be made. Nevertheless, it has been a guiding principle in the prepara tion of this monograph rather to summarize the vastly dis persed material that constitutes the comparative physiology of adaptation to high altitude into a coherent picture, than to provide a comprehensive survey of the field.

Just one of a series of volumes on differing aspects of hypoxia, this authoritative text focuses on cutting-edge research at the interface of hypoxia and biomedicine. Hypoxia – or lack of oxygen – is a constant threat to the human body and its vital organs, one that can take its toll in a number of situations. There are many situations in which the threat is heightened in health and disease, but mechanisms have evolved to lessen its detrimental effects. The International Hypoxia Symposia was founded to enable scientists, clinicians, physiologists, immunologists, mountaineers and other interested individuals to share their experiences of the situations associated with the lack of oxygen and the adaptations that allow us to survive.