Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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Neutrophil (PMN) priming and subsequent responses to the IL-8 presented on pulmonary endothelial surfaces may be crucial determinants of the development of adult respiratory distress syndrome after injury. Elevated plasma ELR+ C-X-C chemokine (CXC) levels might contribute to PMN priming after trauma, but the role of CXCs in priming circulating PMNs is unstudied. We evaluated the interactions of IL-8 and GRO-alpha in priming human PMN calcium fluxes [Ca2+]i within circulatory environments. ⋯ Sufficient stimulation of the CXCR1 terminated this cooperative relationship by downregulating surface expression of CXCR2. This study is the first to report that at physiologic concentrations, C-X-C chemokines can act on circulating human PMNs as an integrated system where CXCR2 agonists, rather than cross-desensitizing CXCR1, act to enhance signaling of IL-8 at CXCR1 both by receptor and post-receptor mechanisms. Such CXCR2 mediated priming of CXCR1/ IL-8 interaction may enhance PMN attack on the lung after injury.
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Comparative Study
A comparison of resuscitation with packed red blood cells and whole blood following hemorrhagic shock in canines.
Resuscitation with crystalloid and packed red blood cells has for the most part replaced the use of plasma and whole blood in the initial treatment of hemorrhagic shock. The effects of such changes on cardiovascular function following hemorrhagic shock remain largely unexplored. We examined cardiovascular function in anesthetized canines subjected to severe hemorrhagic shock. ⋯ PRBC resuscitated dogs showed lower values of mean arterial pressure, cardiac output, rates of ventricular contraction and relaxation and myocardial work. Increasing the maintenance infusion rate of LR (10 mL/kg/h) following PRBC infusion normalized mean arterial pressure, but not other indices of cardiovascular function. Thus, WB, but not PRBC resuscitation restores normal myocardial function during resuscitation from severe hemorrhagic shock.