Sequestration of Blood Plasma Iron as a Marker of Systemic Response to the Blast Lung Injury: Assessment with Electron Paramagnetic Resonance (EPR) Spectroscopy

Abstract : Impact of blast shock waves (SW) with the body wall produces blast lung injuries characterized by bilateral traumatic hemorrhages. Such injuries often have no external signs, are difficult to diagnose, and therefore, are frequently underestimated. Predictive assessment of acute respiratory distress syndrome outcome in SW-related accidents should be based on experimental data from appropriate animal models. Blood plasma transferrin is a major carrier of blood iron essential for proliferative emergency response of hematopoietic and immune systems as well as injured tissue in major trauma. Iron-transferrin complexes ([Fe3+]TRF) can be quantitatively analyzed in blood and tissue samples with low-temperature EPR techniques. We hypothesized that use of EPR techniques in combination with assays for pro-inflammatory cytokines and granulocytes in the peripheral blood and BAL would reveal a pattern of systemic sequestration of [Fe3+]TRF that could be useful for development of biomarkers of the systemic inflammatory response to lung injury. With this goal we (1) analyzed time-dependent dynamics of [Fe3+]TRF in the peripheral blood of rats after impacts of SW generated in a laboratory shock-tube and (2) assayed the fluctuation of granulocyte (PMN) counts and expression of CD11b adhesion molecules on the surface of PMNs during the first 24 h after SW-induced injury.