Pulmonary blast injury increases nitric oxide production, disturbs arginine metabolism, and alters the plasma free amino acid pool in rabbits during the early posttraumatic period

Plasma nitrate + nitrite (nitrates), as final NO products, and free amino a cid pool (FAAP) characteristics, as indicators of protein/amino acid metabo lism, were analyzed in the early (30 min) period following blast injury. Th e experiments were performed on 27 rabbits subjected to pulmonary blast inj ury (experimental group) or not exposed to overpressure (controls), We repo rt that pulmonary blast injury (PBI) induces prompt NO overproduction withi n a very early period. Increased arginine utilization via NO synthase, pres umably associated with its cleavage by arginase, leads to the depletion of the arginine level in arterial plasma 30 min following PBI. Impaired balanc e between arginine utilization and release/resynthesis from endogenous sour ces causes disturbed nutritional status and urea cycle activity. Early iden tification and appropriate management of the changes in amino acid metaboli sm should be included in the evaluation of patients with blast injury. Furt hermore, the results suggest that depleted arterial levels of arginine and NO overproduction may be helpful in diagnosis and prognosis of blast injury . (C) 2000 Academic Press.