【摘要】 目的:探讨氯胺酮对大鼠肺缺血再灌注损伤(LIRI)的保护作用及其机制。方法:将60只SD大鼠随机分为5组:假手术组、模型组、氯胺酮低剂量组(2.5 mg/kg)、氯胺酮中剂量组(5 mg/kg)和氯胺酮高剂量组(10 mg/kg),每组12只。除假手术组外,其他4组均复制LIRI大鼠模型。比较各组大鼠肺组织湿重/干重比值(W/D),采用酶联免疫吸附测定(ELISA)法检测血清中白细胞介素(IL)-6、IL-1β和肿瘤坏死因子(TNF)-α的含量,比色法检测肺组织丙二醛(MDA)含量及髓过氧化物酶(MPO)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,苏木素-伊红(HE)染色法检测肺组织的病理学变化,TUNEL法检测细胞凋亡率,Western blotting法检测磷酸化丝氨酸-苏氨酸蛋白激酶(p-Akt)、p-哺乳动物雷帕霉素靶蛋白(p-mTOR)、p-核因子κB(pNF-κB)p65蛋白表达。结果:与假手术组比较,模型组大鼠肺组织结构损伤严重,肺间质充血水肿,肺间隔变厚,大量炎性细胞浸润和红细胞渗出,W/D比值、细胞凋亡率、MPO活性及IL-6、IL-1β、TNF-α、MDA含量显著升高,SOD、CAT活性显著降低(均P<0.05);氯胺酮处理后肺组织损伤程度明显减轻,仅有少量炎性细胞浸润,肺组织W/D比值、细胞凋亡率、MPO活性及IL-6、IL-1β、TNF-α、MDA含量显著降低,SOD、CAT活性显著升高,且呈剂量依赖性(均P<0.05)。此外,与模型组比较,氯胺酮各剂量组p-NF-κB p65蛋白水平显著降低,p-Akt、p-mTOR蛋白水平显著升高(均P<0.05)。结论:氯胺酮可能通过激活Akt/mTOR信号通路减轻炎症反应及氧化应激,保护大鼠LIRI。更多还原

【Abstract】 Objective: To investigate the protective effect and mechanism of ketamine on lung ischemia reperfusion injury(LIRI) in rats. Methods: A total of 60 SD rats were randomly divided into 5 groups: sham-operation group, model group, low-dose ketamine group(2.5 mg/kg), middle-dose ketamine group(5 mg/kg) and high-dose ketamine group(10 mg/kg), with 12 rats in each group. Except for the sham-operation group, the LIRI rat models were established in other 4 groups. The ratio of wet/dry lung weight(W/D) was calculated. The levels of IL-6, IL-1β and TNF-α in serum were detected by enzyme-linked immunosorbent assay(ELISA). The contents of malondialdehyde(MDA) and myeloperoxidase(MPO), the activities of superoxide dismutase(SOD) and catalase(CAT)in lung tissue were detected by colorimetric test. Hematoxylin-eosin staining was used to observe the pathological changes of lung tissue. TUNEL method was used to detect the apoptosis of lung tissue. The protein expression levels of p-Akt, p-mTOR and p-NF-κB p65 were detected by Western blotting. Results: Compared with the shamoperation group, the lung tissue structure of the model group was seriously damaged, the pulmonary interstitium was congested and edematous, the pulmonary septum became thicker, a large number of inflammatory cells infiltrated and red blood cells exuded, W/D ratio, apoptosis index, the contents of IL-6, IL-1β,TNF-α, MDA and MPO as well as the protein level of p-NF-κB p65 were significantly increased, whereas the contents of SOD and CAT, the protein levels of p-Akt and p-mTOR were decreased(P<0.05). Compared with the model group, the degree of lung injury in ketamine-treated groups was significantly reduced, a small amount of inflammatory cell infiltration was observed, the W/D ratio, apoptosis index, the contents of IL-6, IL-1β and TNF-α in serum, the contents of MDA and MPO in lung tissues and protein level of p-NF-κB p65 were significantly decreased, while the contents of SOD and CAT, the protein levels of p-Akt and p-mTOR were significantly increased(P<0.05). Conclusion: Ketamine may protect LIRI in rats, reduce inflammation and oxidative stress by activating Akt/mTOR signaling pathway.更多还原