多巴胺D2、D3受体在大鼠暂时性局灶性脑缺血中的作用

Effect of dopamine D2 and D3 receptors on temporary local cerebral ischemia on rats

目的 确定多巴胺D2、D3受体是否介导脑缺血时多巴胺的神经毒性作用。方法 用尼龙线阻断大鼠大脑中动脉制备局灶性脑缺血模型 ,用图像分析仪计算梗塞体积 ,激光多普勒血流计监测皮层半暗带脑血流。结果 E 10 1在 2mg/kg剂量时明显减小梗塞体积 ,并使皮层半暗带血流明显升高 ,U 99194A在 15mg/kg剂量时产生与前者相似的效果 ,但是其梗塞体积减小和脑血流升高的程度均较低。结论 D2受体参与介导了脑缺血时多巴胺的神经毒性作用 ,D3受体是否介导该作用仍需进一步研究证实。

Objective To confirm if dopamine D2 and D3 receptors are involved in the neurotoxicity of dopamine during cerebral ischemia. Methods The rat of local cerebral ischemia has prepared by intraluminal MCA occlasion using nylon monofilament. An image analyzing system was used to calculate the infarction volume and a laser flowmater was used to detect the regional cerebral blood flow (rCBF). Results E 101 could obviously reduce the infarction volume and increase the rCBF during cerebral ischemia at the dose of 2mg/kg. U 99194A showed similar effect as E 101(2mg/kg) but with lower degree. Conclusions D2 receptors are involved in the neurotoxicity of dopamine during cerebral ischemia. Further research work is still needed to confirm if D3 receptors also have the same effect.