Microvascular Measurements, 39030, St Lorenzen, Italy.
Department of Radiooncology & Radiotherapy, Klinikum rechts der Isar, Technical University, 81675, Munich, Germany.
Adv Exp Med Biol. 2014;812:25-31. doi: 10.1007/978-1-4939-0620-8_4.
Heterogeneity is a feature of both normal oxygen supply to tissue and of a supply that is disturbed due to a wide range of different pathologies. Here, the physiological importance of heterogeneity of tissue oxygenation is revisited. The anatomical and functional basis for heterogeneity of blood flow, local and regional regulatory mechanisms in normal tissues and the pathophysiology of the failure of regulation will be examined.Under physiological conditions, regulation of blood flow distributions at global, regional and microregional levels play coordinated roles in ensuring adequate O2 supply to all tissue cells. How this is achieved may be organ-/organ layer-specific, depending on its function and priorities to match local O2 delivery to consumption. Examples where these regulatory mechanisms break down under conditions of ischaemia and shock will also be given.In contrast, pathologic heterogeneity in tissue oxygenation resulting from uncontrolled, chaotic growth as seen in malignant tumours represents a pathophysiological status that is not predictable which, in general, is associated with chronic and acute hypoxia. This can have fatal consequences due to hypoxia- induced (mal-)adaptive processes, malignant tumour progression and treatment resistance.
异质性是组织正常供氧和广泛存在的各种病理状态下供氧紊乱的特征。本文重新探讨了组织氧合异质性的生理重要性。本文将检查血流异质性的解剖学和功能基础、正常组织中的局部和区域调节机制以及调节失败的病理生理学。在生理条件下，全球、区域和微区域水平的血流分布调节在确保所有组织细胞获得足够的 O2 供应方面发挥着协调作用。如何实现这一点可能因器官/器官层的功能和优先级而异，以匹配局部 O2 输送与消耗。还将给出在缺血和休克条件下这些调节机制崩溃的例子。相反，恶性肿瘤中失控、混乱生长导致的组织氧合异质性代表了一种不可预测的病理生理状态，通常与慢性和急性缺氧有关。由于缺氧诱导的（不良）适应过程、恶性肿瘤进展和治疗耐药性，这可能会导致致命后果。
