[D-Ala2, D-Leu5]-Enkephalin (Dadle) Reduces Inflammation Responses after Transient Global Ischemia

[D-Ala2, D-Leu5]-Enkephalin (DADLE) is a δ-opioid receptor antagonist and has been shown to reduce neuronal loss in the selectively vulnerable brain regions after transient global ischemia. Here, we investigate whether this protection is mediated by the DADLE's modulation of the postischemia inflammation responses. After implanted with cannula at the right lateral ventricle, rats underwent 10 minutes of transient global ischemia by four vessel occlusion. Rats received a single infusion of DADLE (12.5 nmol) via the intracerebral cannula at the onset of reperfusion. At the time of 72 h after ischemia, we investigated GFAP expression via immunohistochemistry. we also tested the level of MDA and the activities of SOD and CAT. The results show that DADLE can reduce reactive astrocytosis and increase SOD activities. The study reveals the neuroprotection mechanism of DADLE in the ischemic brain is related to reduce inflammation responses.