去甲肾上腺素在百草枯中毒致肺纤维化小鼠模型中的作用研究作者:汤涛陈铜兵王辉来源:《中国医药科学》2022年第08期[摘要]目的探讨去甲肾上腺素(NE)在百草枯中毒导致肺纤维化中的作用。
方法选取苏州大学附属第三医院急诊科收治的41例百草枯中毒患者和6只实验小鼠的血浆,實验组和对照组小鼠各3只,实验组用百草枯处理,高效液相色谱电化学法检测血浆中 NE 浓度。
采用微渗透泵构建小鼠模型,实验组9只,对照组小鼠3只,实验组用百草枯加 NE 处理,对照组仅用百草枯处理。
模拟 NE 受体阻断剂普萘洛尔对百草枯中毒引起的肺纤维化模型,实验组和对照组小鼠各18只,实验组用百草枯加 NE 加普萘洛尔处理,对照组中普萘洛尔换成等量的乙醇。
结果研究显示百草枯中毒患者的 NE 水平显著提高,而中毒实验小鼠 NE 并没有提高。
体外细胞实验显示, NE 在体外可诱导人肺泡Ⅱ型上皮细胞发生上皮间质转化,从而协同百草枯中毒致肺纤维化,小鼠实验发现实验组用 NE 处理的小鼠肺纤维化程度高于对照组。
普萘洛尔实验显示,实验组加了普萘洛尔后百草枯中毒小鼠的肺纤维化程度明显低于对照组。
结论 NE 可能是导致临床百草枯中毒致肺纤维化疗效不佳的重要原因,普萘洛尔在临床上对百草枯中毒所致的肺纤维化有一定的预防作用。
[关键词]百草枯;肺纤维化;去甲肾上腺素;间质转化;普萘洛尔[中图分类号] R965 [文献标识码] A [文章编号]2095-0616(2022)08-0027-05The study on effect of norepinephrine in mouse models of pulmonary fibrosis induced by paraquat poisoningTANG Tao CHEN Tongbing WANG HuiDepartment of Pathology,the First People’s Hospital of Changzhou, Jiangsu, Changzhou 213003, China[Abstract] Objective To investigate the effect of norepinephrine in pulmonary fibrosis induced by paraquat poisoning. Methods The plasma of 41 paraquat poisoning patients who were admitted to the emergency department of the Third Affiliated Hospital of Soochow University and plasma of 6 experimental mice were selected, with 3 mice each in the experimental group and the control group. The experimental group was treated with paraquat, and the high-performance liquid chromatographywith electrochemical detection was used to determine the concentration of norepinephrine in plasma.A micro-osmotic pump was used to construct a mouse model, with 9 mice in the experimental group and 3 mice in the control group. The experimental group was treated with paraquat plus norepinephrine, and the control group was treated with paraquat only. A model of pulmonary fibrosis induced by paraquat poisoning with propranolol, a norepinephrine receptor blocker, was established. There were 18 mice in each of the experimental group and the control group. The experimental group was treated with paraquat plus norepinephrine plus propranolol, and propranolol in the control group was replaced with the same amount of ethanol. Results The study showed that the level of norepinephrine in paraquat poisoned patients was significantly increased, while it did not increase in poisoned experimental mice. In vitro cell experiments showed that norepinephrine induced epithelial-mesenchymal transition in human alveolar type Ⅱ epithelial cells in vitro, thereby cooperating with paraquat poisoning to induce pulmonary fibrosis. Experiments in mice found that the degree of pulmonary fibrosis in mice treated with norepinephrine in the experimental group was higher than that in the control group. The propranolol experiment showed that the degree of pulmonary fibrosis in the paraquat poisoned mice in the experimental group with addition of propranolol was significantly lower than that of the control group. Conclusion Norepinephrine may be an important reason for the poor efficacy of clinical pulmonary fibrosis induced by paraquat poisoning. Propranolol has a certain clinical preventive effect on pulmonary fibrosis induced by paraquat poisoning.[Key words] Paraquat; Pulmonary fibrosis; Norepinephrine; Mesenchymal transition; Propranolol百草枯(paraquat, PQ)中毒是较常见的农药中毒之一,毒性可累及全身多个脏器,但主要以肺为靶器官,早期临床表现为急性肺损伤,后期可出现肺泡内和肺间质纤维化[1-2]。
肺纤维化是 PQ 中毒患者致死的主要原因,病死率高达70%[3]。
全球关于 PQ 中毒致肺纤维化的防治在细胞和动物实验中已经取得不错的疗效[4-6],然而在实际临床治疗中, PQ 中毒致肺纤维化的疗效还不尽如人意,特别是在提高生存率方面。
不同于实验动物,人作为高级情感动物,PQ 中毒患者常处于应激状态。
人应激状态下,机体分泌以去甲肾上腺素(norepinephrine,NE)为代表的压力相关激素[7-9]。
是否正是由于人长期处于应激状态而实验动物没有处于应激状态才导致人的 PQ 中毒致肺纤维化的疗效远低于实验动物?基于此,本研究通过细胞实验和小鼠动物实验探讨 NE 在 PQ 中毒致肺纤维化中的作用。
1材料与方法1.1 细胞及试剂1.1.1 细胞株肺癌人类肺泡基底上皮细胞 A549肺癌胞株购于中国科学院典型培养物保藏委员会细胞库。
A549细胞株可合成卵磷脂,并且含有高度不饱和脂肪酸,广泛用于Ⅱ型肺上皮细胞模型在药物代谢的体外模型。
1.1.2 试剂 DMEM 细胞培养液购于 Invitrogen 公司;胎牛血清购于美国Hyclone公司; E-cadherin 和 Vimentin 抗体购于北京中杉金桥生物有限公司。
1.2 方法1.2.1 细胞培养 A549细胞用含10%灭活胎牛血清、100 U/ml 青霉素、100 U/ml 链霉素和2 mmol/L 谷氨酰胺的高糖 DMEM 完全培养液,于37℃、体积分数为5% CO2培养箱中培养,每2~3天用0.25%胰蛋白酶和0.5% EDTA 混合液传代。
1.2.2 PQ 中毒致肺纤维化小鼠模型建立外源性 NE 微渗透泵实验鼠模型,其中小鼠许可证号:SYKX(苏)2016-0049。
将含有 NE 的微渗透泵植入实验雌性 C57BL/6小鼠背部皮下,可缓慢持续释放 NE。
为解决 NE 半衰期过短的问题,本研究在动物实验部分采用小鼠皮下植入含 NE 的微渗透泵(Alzet model 1004,Durect, Cupertino, CA),24 h 不间断(最长达4周)持续给予外源性 NE。
该泵的工作原理是利用胶囊与所植入部位的组织或器官之间的渗透压的差异运作。
各组小鼠的泵内预先被注入含有56 mM 的 NE,总体积为100μl 的生理盐水(每天1μmol/100 g)。
以不含有药物的生理盐水组作为对照组。
每只泵内还要加入0.2%的抗坏血酸作为抗氧化剂。
另外,在植入小鼠体内前所有微渗透泵要在无菌生理盐水浸泡48 h 以保证在植入体内后即刻开始释放药物。
PQ 中毒致肺纤维化模型采用大小实验鼠均有相关报道,本研究 PQ 中毒肺纤维化造模采用小鼠。
8周龄的 SPF 级 C57BL/6雌性实验鼠于应激第2天一次性腹腔注射 P Q 溶液15 mg/kg 制成 PQ 致肺纤维化模型。