ABSTRACT

The central topic of this chapter is the regulation of polymorphonuclear leukocyte (particularly, neutrophil) activity by circulatory hemodynamics-derived mechanical stresses. Neutrophil activation in the microcirculation plays a critical role in the initiation and control of inflammation (definition: a cascade of biological processes by multiple immune and tissue-specific cell types that242 promote an adaptive response of host tissues to noxious insult) (Medzhitov, 2008). In this respect, neutrophils play an essential role in the acute-stage defense against pathogens (e.g., microorganisms, foreign bodies, and inorganic materials) as well as in the repair and management of tissue damage due to injury. As a consequence of their capacity to express potent antimicrobial and tissue degradative agents during early inflammatory processes, cellular mechanisms must exist to ensure tight regulation of the destructive potential of the polymorphonuclear leukocytes that, if unchecked, may lead to damage to host tissues. Thus, turning off neutrophil inflammatory processes during the resolution stages of wound healing and infection is just as critical as turning on these activities at the time of infection or tissue injury.