异丙酚缓解大鼠脑缺血再灌注损伤及其机制研究

Remission of propofol on cerebral ischemia-reperfusion injury in rats and its mechanism

摘要:

目的： 探究麻醉药物异丙酚缓解大鼠脑缺血再灌注损伤（ischemia reperfusion，IR）的作用及机制。方法： 健康雄性SD大鼠72只，随机分为假手术组、模型组、异丙酚（Pro）组、Pro+DPCPX组、Pro+LY294002组、Pro+DPCPX+LY294002组，每组12只。血管内线栓法阻断大脑中动脉，建立局灶性IR损伤模型，再灌注24 h后进行大鼠神经功能评分，ELISA检测血浆肿瘤坏死因子α（tumor necrosis factor-α，TNF-α）和白介素-1β（interleukin-1β，IL-1β）含量，TTC染色检测脑梗死体积，免疫组织化学法检测Bcl-2阳性细胞表达情况，Western blot检测Akt、p-Akt表达量。结果： 与模型组大鼠相比，异丙酚能够有效降低IR大鼠神经功能评分，缩小脑梗死体积，提高脑组织Bcl-2阳性细胞表达率，有效降低IR大鼠血浆炎性因子TNF-α和IL-1β的表达水平（P<0.05）。与此同时，异丙酚能够明显升高大脑皮质区p-Akt表达（P<0.05），异丙酚干预的IR大鼠体内PI3K/Akt信号通路呈高度激活状态。当实验大鼠加PI3K抑制剂LY294002处理时，异丙酚的神经保护作用被明显抑制，失去治疗效果。其抑制作用与A1R受体拮抗剂DPCPX效果相当。结论： 异丙酚能够在IR大鼠模型中激活A1R，通过抑制兴奋性氨基酸的毒性，促进p-Akt表达，进一步激活PI3K/Akt信号通路，上调脑组织Bcl-2表达水平，发挥抗神经细胞凋亡作用，同时下调炎性因子TNF-α和IL-1β表达，减轻机体的炎症反应，发挥良好的脑缺血再灌注损伤缓解作用。

Abstract:

Objective: To investigate the effect and mechanism of anesthesia drug propofol on cerebral ischemia-reperfusion (IR) injury in rats. Methods: Seventy-two healthy male SD rats were randomly divided into sham operation group, model group, propofol (Pro) group, Pro+DPCPX group, Pro+LY294002 group, Pro+DPCPX+LY294002 group, with 12 rats in each group. The middle cerebral artery was blocked by the intravascular endothelial method, and a focal cerebral IR injury model was established. Rats were scored for neurological function 24 hours after reperfusion. Plasma levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured by Enzyme-linked immunosorbent assay (ELISA). The brain was detected by Triphenyl tetrazolium chloride (TTC) staining infarct volume, the expression of Bcl-2 positive cells was detected by immunohistochemistry, and the expression of Akt and p-Akt was detected by Western blot. Results: Compared with the model group, propofol effectively reduced the neurological score of IR rats and the volume of cerebral infarction, increased the expression rate of Bcl-2 positive cells in brain tissue, and effectively reduced the expression levels of plasma inflammatory factor TNF-α and IL-1β in IR rats (P<0.05). At the same time, propofol significantly increased the level of p-Akt expression in the cerebral cortex (P<0.05), and the PI3K/Akt signaling pathway in IR rats interfered with by propofol was highly activated. When the experimental rats were treated with the PI3K in-hibitor LY294002, the neuroprotective effect of propofol was significantly inhibited and the therapy was ineffective. Its in-hibitory effect was comparable to that of A1R receptor antagonist DPCPX. Conclusion: Propofol can activate A1R in IR rat models by inhibiting the excitatory amino acid toxicity, promote the expression of p-Akt, further activate the PI3K/Akt signaling pathway, up-regulate the expression level of Bcl-2 in brain tissue, and exert anti-apoptotic effects. At the same time, it can down-regulate the expression of inflammatory factors TNF-α and IL-1β, reduce the body’s inflammatory response, and thus exerts a good therapeutic effect.