Objective: To explore the antioxidant effect of moxibustion on vascular endothelial function and the under-lying mechanism.
Methods: Forty male SD rats were randomly divided into blank, model, moxibustion and endothelial nitric oxide synthase (eNOS) inhibitor groups, with 10 rats in each group. Hyperlipidemia rat model was established by high fat diet for 8 weeks. Rats in the moxibustion group received 45 ℃ moxibustion at "Zusanli" (ST36) for 10 min once daily for consecutive 4 weeks. Rats in the eNOS inhibitor group received intraperitoneal injection of eNOS inhibitor L-NAME (1 mg/100 g) at the same time of moxibustion intervention. The morphology of abdominal aorta endothelium was observed by HE staining. Lipid deposition in abdominal aorta was observed by oil red O staining. The contents of total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) in serum and reactive oxygen species (ROS), nitric oxide (NO), superoxide dismutase (SOD), oxidized LDL lipoprotein (ox-LDL), endothelin-1 (ET-1), eNOS, malondialdehyde (MDA) in serum and abdominal aorta were determined by ELISA. The expression of eNOS in abdominal aorta was detected by immunofluorescence.
Results: HE staining of the abdominal aorta showed no significant pathological abnormality in the blank group; the endovascular cortex was rough, and the inner, media and outer membrane were rough in the model group; the nucleus and surrounding tissue structure were clear and the vascular wall was smooth in the moxibustion group; abdominal aorta texture was rough in the eNOS inhibitor group. Compared with the blank group, the area of oil red O staining in abdominal aorta increased (P<0.05); the contents of serum TC, TG and LDL-C increased (P<0.01, P<0.05) while HDL-C decreased (P<0.05); the contents of ET-1 in serum and abdominal aorta were increased (P<0.01, P<0.05) while the contents of NO and eNOS were decreased (P<0.05, P<0.001); the contents of ROS, ox-LDL and MDA in serum and abdominal aorta were increased (P<0.001, P<0.01, P<0.000 1) while the content of SOD in abdominal aorta was decreased (P<0.000 1); the expression level of eNOS in abdominal aorta was decreased (P<0.05) in the model group. Compared with the model group, the area of oil red O staining in abdominal aorta decreased (P<0.05); the contents of TC, TG and LDL-C in serum decreased (P<0.05) while HDL-C increased (P<0.05); the contents of ET-1 in serum and abdominal aorta were decreased (P<0.01, P<0.05) while the contents of NO and eNOS in abdominal aorta were increased (P<0.001, P<0.01); the contents of ROS and MDA in serum and abdominal aorta were decreased (P<0.001, P<0.01, P<0.05), the content of ox-LDL was decreased (P<0.01) and the content of SOD was increased (P<0.000 1) in abdominal aorta; the expression level of eNOS in abdominal aorta was increased (P<0.05) in the moxibustion group. Compared with the moxibustion group, the contents of serum TC, LDL-C and MDA in the eNOS inhibitor group were increased (P<0.05); the contents of ET-1, ROS, ox-LDL and MDA in abdominal aorta were increased (P<0.05), the contents of NO, eNOS and SOD were decreased (P<0.05); the expression level of eNOS in abdominal aorta was decreased (P<0.05).
Conclusion: 45 ℃ moxibustion at ST36 can protect and repair vascular endothelial injury in abdominal aorta of hyperlipidemia rats and improve the oxidative stress of vascular endothelium.
目的：探究艾灸改善血管内皮功能的抗氧化效应机制。方法：将40只雄性SD大鼠随机分为空白组、模型组、艾灸组和eNOS抑制剂组，每组10只。采用高脂饲料喂养8周制备高脂血症大鼠模型。艾灸组予45 ℃艾灸“足三里”干预，10 min/次，eNOS抑制剂组在艾灸干预的同时予腹腔注射eNOS抑制剂，均1次/d，连续干预4周。采用HE染色法观察大鼠腹主动脉血管内皮形态；油红O脂肪染色法检测各组大鼠腹主动脉脂肪沉积情况；ELISA法检测血清及腹主动脉中血管活性物质及氧化应激相关指标水平；免疫荧光法检测大鼠腹主动脉中内皮型一氧化氮合酶(eNOS)的表达。结果：空白组腹主动脉呈粉红色，细胞核及血管周围组织结构清晰，血管内皮层光滑，血管内膜、中膜及外膜层纹理清晰；模型组腹主动脉呈暗粉色，颜色较淡，血管内皮层毛糙，血管内膜、中膜及外膜层纹理粗糙；艾灸组腹主动脉呈粉红色，细胞核及周围组织结构清晰，血管壁光滑；eNOS抑制剂组腹主动脉呈暗粉色，颜色较淡，纹理较粗糙。与空白组比较，模型组腹主动脉油红O染色面积比增大(P<0.05)；血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇（LDL-C）含量升高(P<0.01，P<0.05)，高密度脂蛋白胆固醇(HDL-C)含量降低(P<0.05)；血清及腹主动脉中内皮素-1(ET-1)含量升高(P<0.01，P<0.05)，一氧化氮(NO)、eNOS含量降低(P<0.05，P<0.001)；血清及腹主动脉中活性氧(ROS)、氧化型低密度脂蛋白(ox-LDL)、丙二醛(MDA)水平升高(P<0.001，P<0.01，P<0.000 1)，腹主动脉中超氧化物歧化酶(SOD)水平降低(P<0.000 1)；腹主动脉中eNOS荧光表达水平降低(P<0.05)。与模型组比较，艾灸组腹主动脉油红O染色面积比减小(P<0.05)；血清TC、TG、LDL-C含量降低(P<0.05)，HDL-C含量升高(P<0.05)；血清及腹主动脉中ET-1含量降低(P<0.01，P<0.05)，腹主动脉中NO、eNOS含量升高(P<0.001，P<0.01)；血清ROS、MDA水平降低(P<0.001，P<0.01)，腹主动脉中ROS、ox-LDL、MDA水平降低(P<0.05，P<0.01，P<0.001)，腹主动脉中SOD水平升高(P<0.000 1)；腹主动脉中eNOS荧光表达水平升高(P<0.05)。与艾灸组比较，eNOS抑制剂组血清TC、LDL-C、MDA水平升高(P<0.05)；腹主动脉中ET-1含量及ROS、ox-LDL、MDA水平升高(P<0.05), NO、eNOS含量及SOD水平降低(P<0.05);腹主动脉中eNOS荧光表达水平降低（P<0.05）。结论：45 ℃艾灸“足三里”可以保护和修复高脂血症大鼠腹主动脉的血管内皮损伤，改善血管内皮的氧化应激。.
Keywords: Abdominal aorta; Endothelial nitric oxide synthase; Hyperlipidemia; Moxibustion; Oxidative stress.