Hyperbaric Oxygen
Treatment after the Blast Injury of Rabbitbrain the Expression of AQP4 and PWI
in the Study Phase
23. June 2012 · Comments
Off · Categories: Surgery ·
Tags: aquaporin-4, brain injury, hyperbaric oxygen treatment, magnetic resonance perfusion imaging, Rabbit
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Title
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Hyperbaric Oxygen Treatment after
the Blast Injury of Rabbit brain the Expression of AQP4 and PWI in the Study
Phase
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Abstract
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Objective:To establish explosive
brain injury model in rabbits;To investigate the expression of aquaporin
4(AQP4) in model of explosive brain of rabbits injury,and perfusion changes
in the expression, to explore the formation of brain edema after blast injury
mechanism, and early hyperbaric oxygen treatment of traumatic brain edema
formation and development of the role of early treatment for clinical
hyperbaric oxygen provide the basis for traumatic brain edema.Method:①30 New Zealand white rabbits, weighing 2.0 ~ 2.5kg, in
accordance with the vertical distance between the detonators and the skull
group, were randomly divided into groups 5.0cm, 6.5cm group, 8.0cm group, n =
10. 600mg TNT equivalent of paper detonators were used to explode
respectively 5.0cm, 6.5cm, and 8.0cm vertical distance from the top of the
rabbit head, observing animal survival after injury, and using magnetic
resonance imaging methods to understand the pathology and brain damage in
each group.②150
New Zealand rabbits were randomly divided into non-treatment group, treatment
group and control group, and 10 rabbits were in the latter. Explosive brain
injury model was made by paper detonator. Injuryed rabbits were randomly
divided into 1h、6h、12h、24h、72h、7d、14d ,14 groups according to a further killed time points
after injury, and each group has 10 rabbits. Using dry weight to measure the
content water in brain tissue, and using RT-PCR method and image analysis to
detect the group at different time points aquaporin 4 (AQP4)mRNA expression,
and Western blotting to measure the expression of AQP-4 in brain tissue.
Using magnetic resonance perfusion imaging ( PWI) injury time points detected
in brain tissue blood perfusion. Finally, it was used for statistical
analysis.Results:①5
rabbits died immediately after injury and 4 rabbits died within 3 days in
group 5.0cm,and only one survived more than 7 days;The rabbit has appeared
most extensive brain contusion, cortical surface vessel rupture occurs, and
significant fragmentation in brain tissue, large subdural hematoma, and
significant brain stem contusion. All rabbits in group 6.5cm survived more
than 7 days,except that 1 rabbit died on the 4th day after injury because of
inability eating. 4 rabbits occurred epilepsy and got paralysis of limbs;
Pathology observed in the survival of the rabbits had cerebral cortex partial
rupture of blood vessels, brain edema and obvious laceration and contusion
lesions clear boundary with the surrounding brain tissue. All rabbits in
group 8.0cm survived, but showed no significant changes in the brain.②Blast injury after contusion brain 1h aquaporin 4 (AQP4)
mRNA expression increased, and in turn increased, 72h peak (P <0.05), 7d
pm down. Brain tissue aquaporin 4 (AQP4) began to express 1h after injury
increases, and 72h reached its peak (P <0.05), it turned to down after 7d,
but it still maintained on a high level. Brain tissue water content and water
aquaporin 4 (AQP4) expression were the same. The correlation analysis,
aquaporin 4 (AQP4) expression and brain tissue water content was positively
correlated (r=0.8767,P<0.001). The hyperbaric oxygen treatment, aquaporin
4 (AQP4) expression at different time points are different degrees of
decline, aquaporin 4 (AQP4) expression of injury group compared with control
group at after 6h points were lower (P <0.05 ). Blast injury after
contusion brain 1h AQP4 mRNA expression increased, and in turn increased, 72h
peak (P <0.05), 7d pm down, but still maintain a high level. After
intervention by hyperbaric oxygen, in 6h, AQP4 mRNA expression was
significantly lower than the injury to 14d is still significantly lower (P
<0.05). Post-traumatic cerebral contusion early peripheral blood perfusion
decreased significantly to 6 hours after injury, blood perfusion decreased to
the lowest (P <0.05), then gradually increased, and maintain a perfusion
(close to the control group) for 2 weeks. The hyperbaric oxygen treatment
group than in the early trauma group (1-6 hours after injury) perfusion
decreased more significantly. 12 hours after infusion began to rise, and
non-treatment group was essentially flat.Conclusion:①Detonators and the vertical distance of the skull 6.5cm,
can produce good stability, repeatability strong blast injury model of rabbit
brain.②The
expression of post-traumatic brain aquaporin 4 (AQP4) in traumatic brain is
closely related to the formation and development of injury and brain edema.
Aquaporin 4 (AQP4) expression may be associated with brain ischemia and
hypoxia in the Hyperbaric oxygen intervention aquaporin 4 (AQP4) expression
was significantly reduced. Instead, the blood perfusion than the control
group and non-treatment group decreased significantly, suggesting that brain
tissue oxygen levels of early trauma and aquaporin 4 (AQP4) expression is
closely related to early hyperbaric oxygen therapy on the relief plays an
important role in traumatic brain edema. Early hyperbaric oxygen therapy can
improve cerebral blood oxygen contusion, increased blood oxygen content, ease
the secondary cerebral hypoxia caused by cerebral edema.
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