Influence Of Hyperbaric Oxygen Therapy On Expression Of Matrix Metalloproteinases And Behavior Outcomevs After Traumatic Brain Injury In Rats

Objective: matrix metalloproteinases (MMPs) play an important role in secondary brain damage after traumatic brain injury (TBI).Recent evidences suggest that MMPs contribute to acute edema and lesion formation following brain ischemic lesion and TBI. Many Experimental and clinical studies have reported that hyperbaric oxygen therapy (HBOT) may be beneficial in various noncerebral and cerebral inflammatory diseases. The mechanisms of the beneficial effects of HBOT are not clearly understood.The purpose of this study was to evaluate the effects of HBOT on the expression of MMPs in the rat model of TBI .Methods: Male Sprague–Dawley rats were traumatized by the Feeney's brain injury model. The rats were randomly divided into four groups(n=30 for each group): sham-operated, TBI with subsequent HBOT (2ATA),and TBI with normobaric oxygenation (1 ATA), not treated after TBI。The animals were killed at 6, 24, 72 h and 5,7 days. Immunohistochemical staining for MMP-2 and -9 and behavior outcomes was also performed and the results were quantitatively evaluated by image analysis. Results: In the animals treated by HBOT, the expression of MMP-9 was significantly lower comparison with that in the nontreated animals and those treated by normobaric oxygen. Staining for MMP-2 did not change significantly. In the animals treated by HBOT, behavior outcomes was significantly improved comparison with that in the nontreated animals and those treated by normobaric oxygen.Conclusions: The decline of MMP-9 expression after HBOT may contribute to protection of brain tissue in the perilesional area. HBOT improve behavior function.