Microcirculatory derangements in acute pancreatitis.

During the past decade, a considerable number of experimental studies have confirmed the hypothesis that microcirculatory derangements play a pivotal role in the pathogenesis of acute pancreatitis, including the process of conversion from edematous to necrotizing injury. Predominant microcirculatory disorders are nutritive capillary perfusion failure, with the consequence of prolonged focal hypoxia or anoxia, and inflammation-associated microvascular leukocyte recruitment, CD11b- and intercellular adhesion molecule (ICAM)-1-mediated leukocyte-endothelial cell interaction and loss of endothelial integrity, which may result in both edema formation and necrosis. A variety of proinflammatory mediators, such as oxygen radicals, leukotrienes, platelet-activating factor, and interleukins, but also bradykinin and endothelins, seem to be involved in triggering the manifestations of these microcirculatory disorders. In contrast, the anti-inflammatory interleukin-10, as well as nitric oxide, are thought to be capable of protecting from these pancreatitis-associated microvascular injuries. This knowledge may be encouraging for the development of novel therapeutic strategies, aiming at the attenuation of microcirculatory disorders, and, thus, preventing tissue injury in acute pancreatitis.