The complex pressure wave (blast) generated by some explosions causes pulmonary pathological changes which resemble the histological findings of the
adult respiratory distress syndrome (ARDS). The development of indirect neurotrauma following experimental pulmonary
blast injury has been shown previously. The purpose of this study was to evaluate lung and brainstem total tissue
magnesium concentrations in adult rabbits following pulmonary
blast injury. In order to assess the interrelationship between
magnesium and other secondary injury factors, total
calcium and high energy
phosphate (
phosphocreatine, PCr;
adenosine triphosphate,
ATP) contents were simultaneously measured. Twenty adult male rabbits were divided into two groups. Group C (n = 10) served as control, while group B (n = 10) was subjected to a focused blast wave, generated in laboratory conditions using an air-driven
shock tube. Moderate pulmonary
blast injury was verified by histological examination in group B. Total tissue
magnesium and
calcium contents were measured by atomic absorption spectrophotometry in the lungs and brainstem of adult rabbits 30 min following blast overpressure and in their uninjured controls. Simultaneously, PCr and
ATP contents were measured by fluorimetric enzymatic analyses in same structures. Lung and brainstem water contents were determined by wet weight to dry weight ratio. Blast overpressure to the lungs induced significant
magnesium depletion, increased
calcium and decreased the Mg/Ca ratio in lung tissue of injured animals. Increases in water content and PCr/
ATP ratio were also observed. Significant correlations between these Mg/Ca and PCr/
ATP and between Mg and
ATP parameters confirmed the functional relationship between
magnesium depletion and impaired bioenergetic state in indirect neurotrauma in adult rabbits through blast overpressure.