血管内皮细胞损伤和修复与2型糖尿病阿司匹林抵抗的相关性研究

目的:研究血管内皮细胞损伤和修复与2型糖尿病阿司匹林抵抗的相关性。方法:选择2013年—2014年收治的2型糖尿病患者310例,其中符合入选标准298例。根据TEG检测结果将患者分为阿司匹林抵抗组42例和阿司匹林敏感组256例。所有患者每天口服>100 mg的阿司匹林,1周后,抽取患者静脉血,置于枸橼酸和肝素试管中。检测血小板抑制率。以患者发病时间为起点进行为期12个月的随访,检测患者外周血中的血管内皮细胞的数量。结果:患者服用阿司匹林1周后,阿司匹林敏感组和阿司匹林抵抗组循环内内皮细胞的数量为(4.2±1.6)个和(3.3±1.1)个,随访1年后分别为(5.2±1.4)个和(2.2±0.7)个,两组患者在不同时间段循环内内皮细胞数量比较,差异有统计学意义,P<0.05。结论:血管内皮细胞损伤与阿司匹林抵抗具有明显的相关性,科学有效地降低阿司匹林抵抗率能够有效降低糖尿病患者并发心脑血管血栓性疾病的发生率,减少血管内皮细胞的损伤程度。

益气活血中药防治大鼠血管内皮细胞损伤的实验研究

目的 :建立大鼠VEC损伤模型 ,观察益气活血中药是否具有防治大鼠VEC损伤的作用。方法 :SD大鼠 30只 ,随机分为正常对照组、模型组、益气活血组各 10只。建立大鼠VEC损伤模型 ,检测并比较CEC计数、t PA、PAI活性、6 Keto PGF1α含量及PAgTmax等指标变化。结果 :益气活血组与模型组比较 :CEC计数明显减少 ,t PA活性明显增强 ,PAI活性降低 ,活性型t PA升高 ,6 Keto PGF1α 含量升高 ,PAgTmax(P <0 .0 1～ 0 .0 5 )。结论 :益气活血中药具有良好的VEC保护作用 ,能改善和调节VEC的内分泌功能 ,增强其抗凝及纤溶活性。这为益气活血中药有效防治心脑血管疾病的作用机制提供了新的实验依据。

Effects of warm ischemia time on biliary injury in rat liver transplantation

AIM:To investigate the effect of different secondary warm ischemia time (SWIT) on bile duct injury in livertransplanted rats. METHODS:Forty-eight male inbred Sprague-Dawley rats were randomly assigned into four groups:a shamoperation group and three groups with secondary biliary warm ischemia time of 0 min, 10 min and 20 min. A rat model of autologous liver transplantation under ether anesthesia was established, and six rats were killed in each group and blood samples and the median lobe of the liver were collected for assay at 6 h and 24 h after hepatic arterial reperfusion. RESULTS:With prolongation of biliary warm ischemia time, the level of vascular endothelial growth factor-A was significantly decreased, and the value at 24 h was higher than that at 6 h after hepatic arterial reperfusion, but with no significant difference. The extended biliary SWIT led to a significant increase in bile duct epithelial cell apoptosis, and a decrease in the number of blood vessels, the bile duct surrounding the blood vessels and bile duct epithelial cell proliferation in the early postoperative portal area. Pathologic examinations showed that inflammation of the rat portal area was aggravated, and biliary epithelial cell injury was significantly worsened. CONCLUSION:A prolonged biliary warm ischemia time results in aggravated injury of the bile duct and the surrounding vascular plexus in rat autologous orthotopic liver transplantation.

Platelet-mediated adhesion facilitates leukocyte sequestration in hypoxia-reoxygenated microvessels

Leukocyte transendothelial migration and sequestration are two distinct outcomes following leukocyte adhesion to endotheli- um during ischemia-reperfusion injury, in which platelets may play a pivotal role. In the present study, we established an in vitro hypoxia-reoxygenation model to mimic ischemia-reperfusion injury and found platelet pre-incubation significantly in- creased leukocyte adhesion to endothelial cells after hyoxia-reoxygenation （over 67%）. Blockade of endothelial-cell-expressed adhesion molecules inhibited leukocyte direct adhesion to endothelial cells, while platelet-mediated leukocyte adhesion was suppressed by blockade of platelet-expressed adhesion molecules. Further experiments revealed platelets acted as a bridge to mediate leukocyte adhesion, and platelet-mediated adhesion was the predominant pattern in the presence of platelets. However, platelet pre-incubation significantly suppressed leukocyte transendothelial migration after hypoxia-reoxygenation （over 31%）, which could be aggravated by blockade of endothelial-cell-expressed adhesion molecules, but alleviated by blockade of plate- let-expressed adhesion molecules. This would indicate that platelet-mediated adhesion disrupted leukocyte transendothelial migration. An in vivo meseuteric ischemia-reperfusion model demonstrated leukocyte transfusion alone caused mild leukocyte adhesion to reperfused vessels and subsequent leukocyte infiltration, while simultaneous leukocyte and platelet transfusion led to massive leukocyte adhesion and sequestration within reperfused microvessels. Our studies revealed platelets enhanced leu- kocyte adhesion to endothelial cells, but suppressed leukocyte transendothelial migration. Overall, this leads to leukocyte se- questration in hypoxia-reoxygenated microvessels.

Changes in pulmonary vascular endothelial cells after acute lung injury induced by bone marrow extract injection in rabbits

Objective: To investigate the changes of the markers of pulmonary vascular endothelial cells (PVECs) after acute lung injury (ALI) induced by bone marrow extract (BME) injection in rabbits. Methods: Thirty one rabbits were randomized into control (CG, n=10) and experimental groups (EG, n=21). The rabbits in EG were injected with homogeneous bone marrow extract (0.35 ml/kg, 2 ml/h) at a slow and continuous rate through the jugular vein to establish the model of ALI. At 6 h after the injection, the number of circulating endothelial cells (CECs) in the blood, contents of granule membrane protein 140 (GMP 140), angiotensin converting enzyme (ACE) and endothelin 1 (ET 1) in the plasma and the content of GMP 140 in the pulmonary tissue were determined at various time intervals. Then the animals were killed and routine pathological examination and electron microscopy were performed to observe the changes in the pulmonary tissue. Results: The levels of plasma GMP 140, ACE, ET 1 and CECs were significantly increased in the early stage ( 0.5 h) and remained higher for 6 h. The marked increase of plasma GMP 140 (3.25 times) in the early stage was negatively correlated to PaO 2, but positively to other parameters. IHC staining showed that the GMP 140 on the surface of PVECs became weak. Conclusions: BME injection at slow and continuous rate can establish an acceptable model of ALI. Determination of plasma GMP 140 might be an important measure for the early surveillance and the evaluation of prognosis of ALI in clinical management of serious traffic accidents.

Tie2 mRNA in peripheral blood： a new marker to assess damage of endothelial cells in a rat model of sepsis

Objective： To evaluate the endothelial cell damage by detecting the circulating Tie2 mRNA level in a rat model of sepsis. Methods： The model of sepsis was established by cecal ligation and puncture （CLP） in 90 rats which were divided into 6 groups： normal, sham, CLP-3 h, CLP-6 h, CLP- 12 h and CLP-24 h. Serum biochemical markers were detected by automatic biochemical analyzer. Serum IL-6 was measured with enzyme linked immunosorbent assay. The vascular permeability of liver, kidney, lung and heart was detected with Evans blue. Circulating endothelial cells （CEC） were separated using density gradient separation and counted. Total RNA of whole blood were extracted and the mRNA levels of two endothelial specific genes, Tie2 and vascular endothelial growth factor receptor 2 （VEGFR2）, were measured by quantitative real-time PCR. Results： The level of serum biochemical indexes increased after CLP. The amount of serum IL-6 in CLP-6 h, 12 h,and 24 h group was increased 6.5-fold （P〈 0.05）, 8.4-fold （P〈 0.01 ）, and 13.3-fold （P〈0.001 ） compared with normal group （ 170.68 pg/mli42.46 pg/ml） respectively （F= 14.319, P〈0.001）. Significantly increased organ vasopermeability of liver, kidney, lung and heart was observed after CLP respectively. The number of CEC peaked （11.83±1.94） 3 hours after CLP compared with normal control （5.33±1.21, P〈0.05）, and then decreased gradually （F=54.183, P〈0.001）. The mRNA level of Tie2 in CLP-3 h group （3.47±1.47） was also markedly higher than that in other groups （F=10.640, P〈0.001 ）. Conclusion： Using quantitative real-time PCR to measure the level of Tie2 mRNA in peripheral blood is a simple and relatively sensitive method to evaluate the damage of endothelial cells.