| Objective:Background and Purpose—Docosahexaenoic acid (DHA;22:6n-3), an ω-3essential fatty acid family member, is the precursor of neuroprotectin D1, which down-regulates apoptosis and, in turn, promotes cell survival. This study examined the protective effect of DHA on brain injury and hemorrhagic transformation(HT) in a rat model of focal ischemia with hyperglycemia.Methods:Sprague-Dawley rats were anesthetized and subjected to1.5h of middle cerebral artery occlusion (MCAO). Animals were treated with either DHA or an equivalent volume of saline intravenously1.5h after MCAO onset. All the rats received an injection of50%dextrose (6ml/kg intraperitoneally)5min before MCAO to induce acute hyperglycemia. At24h after MCAO rats were performed different sequences of MRI and were killed for blood-brain barrier permeability, hemorrhage volume, hemoglobin content test,infarct volume measurements, and immunohistochemistry dyeing.Results:DHA improved neurological behavior performance, and attenuated infarct volume, HT (2.17±1.76μL vs10.37±20.05μL, P<0.01) and Evans blue extravasation (10.82±2.48μg/g brain vs16.07±2.33mg/g brain, P<0.01) at24h after MCAO. Immunohistochemistry analysis revealed that the expression of collagen type IV significantly increased (4.28±0.58%vs2.97±0.43%, P<0.01) and the ICAM-1expression was significantly decreased (2.91±0.98%vs6.47±1.27%, P<0.01) in DHA treated group as compared with saline treated group.Conclusion:DHA can attenuate hyperglycemia enhanced hemorrhagic transformation, reduce infarct volume and improve neurological deficit, which covers mechanisms of keeping stability of BBB and down-regulating the expression of ICAM-1. These effects may associate with decreased oxidative stress and inflammation in the vascular wall. |
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