Objective To evaluate the regional cerebral metabolic changes in different episodes by magnetic resonance spectroscopy (MRS) after explosive brain injury in rabbits. Methods Fortyfive New Zealand white rabbits were randomly divided into eight groups, ie, normal control group( 10 rabbits) and trauma group (35 rabbits). The explosive injury in trauma group was induced by explosion of 600 mg TNT equivalent of paper detonators at 6.5 cm above the rabbit brain. The rabbits in trauma group was divided into 1,6, 12, 24 hours, 3, 7, 14 days subgroups (6 rabbits per group). The survival rate was observed at different time points after explosive injury. The MRS was used to detect the regional cerebral metabolic changes including N-acetylaspartate (NAA)/creatine (Cr) ratio and choline(Cho)/Cr ratio as well as evolution of blast injuries over time. Results The rabbits survived for overseven days in the trauma groups, with typical brain contusion manifested by pathological and conventional MRI. Compared with the normal control group, the NAA/Cr ratio was markedly decreased at one hour after injury, slightly rose again at 24 hours and fell again after seven days. The Cho/Cr ratio was markedly increased at one hour after injury, slightly fell again at 12 hours and rose again at three days after injury.Conclusions MRS can manifest the regional cerebral metabolic changes of rabbits with explosive injury at different time points and hence provide a theoretical basis for understanding the local tissue changes and determining the type of tissue damage after blast injury.

Objective To investigate the protective effect of meglumine adenosine cyclosphosp (MAC) on the cerebral ischemia-reperfusion (I/R) injury in rabbits.Methods Twenty four healthy rabbits were randomly divided into control group (n =6),I/R group (n =6),MAC pretreated group (n =6),and MAC treated group (n =6).Cerebral ischemia-reperfusion injury model was made by separating and electrocoagulating vertebral arteries and clipping common carotid arteries in the latter 3 groups after anesthesia.The sham-operated group underwent vessel separation without clipping.L/R group was administered with nothing,while MAC pretreated group with MAC before ischemia,and MAC treated group with MAC just after ischemia.Blood was gathered from jugular vein before ischemia,and 30 min,1 h,and 2 h after reperfusion for testing IL-8,superoxide dismutase (SOD) and malondialdehyde (MDA).The brain tissue slice was observed by optical microscope.Results Compared to control group and before ischemia,the levels of IL-8 and SOD in serum were significantly increased and decreased,and the levels of MDA was significantly increased at 30 min after reperfusion in I/R group; the levels of IL-8 and MDA in serum were significantly increased,and the levels of SOD in serum was significantly decreased at 1 h and 2 h after reperfusion in I/R group.The levels of IL-8 in serum was less at 30 min and 1 h and 2 h after reperfusion in MAC pretreated group than in I/R group.At 1 h and 2 h after reperfusion,the levels of MDA in serum was less and the levels of SOD in serum was higher in MAC pretreated group than in I/R group.At 1 h and 2 h after reperfusion,the levels of IL-8 in serum were less and the levels of SOD in serum were higher in MAC treated group than in I/R group.The levels of MDA in serum were less at 2 h after reperfusion in MAC treated group than in I/R group.Compared to I/R group,pathological change was lighter in the MAC pretreated and MAC treated group.Conclusions MAC has a fine cerebral-protective effect and has no side effect.