The effects of Mannitol combined with Nimodipine and Dexamethasone on NO, SOD and MDA in rabbits following acute cerebral ischemia

Objective To study the neuroprotective effects related to time-framing of Mannitol combined with Nimodipine and Dexamethasone in treatment of acute cerebral ischemia in rabbits. Methods Forty-two rabbits were randomly divided into seven groups (Group A: sham-operated group; Group B: ischemic model group; Group C: medicated at 1 hour after onset of ischemia; Group D: medicated at 3 hours after onset of ischemia; Group E: medicated at 6 hours after onset of ischemia; Group F: medicated at 12 hours after onset of ischemia; Group G: medicated at 24 hours after onset of ischemia). All the rabbits were occluded of internal carotid artery on one side (the internal carotid artery in Group A was dissected but not occluded), and then subjected to treatments at 1, 3, 6, 12 and 24 hours per protocol (only normal saline in equivalent volumes was given to Groups A and B at these time spots). The serum levels of NO, SOD and MDA were measured in these rabbits one hour after each medication. Results (1) Levels of NO, SOD and MDA showed no changes across all time spots; (2) compared with group A, the contents of NO and MDA were higher (all P0.01); SOD contents were lower (P0.01) in Group B at all time spots. (3) Over time in Group B, SOD content decreased and levels of NO and MDA increased (all P0.05). (4) The content of NO and MDA were significantly lower, and SOD content was greatly higher in all medicated groups than those in ischemic model group (all P0.01). (4) Across all medicated groups at different time spots, SOD content was the highest and levels of NO and MDA were the lowest in Group C, whereas SOD content was the lowest and levels of NO and MDA were the highest in Group G (all P0.05). Conclusion Acute ischemia results in serious damage to brain tissue, which may deteriorate over time. Combined use of Mannitol, Nimodipine and Dexamethasone may provide more neuroprotective effects against ischemic cerebral injury. These effects are expected to be more evident and with better outcomes when medication is started earlier.