内皮素-1对缺氧/复氧所致心肌细胞凋亡的影响

目的探讨在缺氧/复氧过程中不同时期给予内皮素-1（ET-1）对缺氧/复氧所致心肌损伤与凋亡的影响。方法乳鼠心肌细胞缺氧/复氧模型,流式细胞仪检测心肌细胞凋亡,Hoechst 33258染色计算凋亡率,试剂盒检测乳酸脱氢酶（LDH）的活性。结果ET-1预处理组（EP）细胞生存率较缺氧复氧组（HR）提高,凋亡率下降,LDH活性下降;ET-1缺氧即刻处理组（EH）细胞生存率较HR组降低,凋亡率升高,LDH释放量增加;ET-1复氧处理组（ER）的细胞生存率、凋亡率及LDH活性与HR组均无统计学差异。结论ET-1预处理有心肌细胞保护作用,ET-1缺氧时有促进心肌细胞损伤和凋亡的作用。     

Early intervention with a potent endothelin-A/endothelin-B receptor antagonist aggravates left ventricular remodeling after myocardial infarction in rats

Intervention with selective endothelin (ET)A receptor antagonists within 24 h after myocardial infarction (MI) in rats has been reported to aggravate left ventricular (LV) remodeling. In contrast, beneficial effects are reported when initiation of treatment is delayed 7 days or more after MI. However, bosentan, a mixed ET_A/ET_B receptor antagonist with low affinity for the ET receptors, has been shown to exert beneficial effects independent of the time point of initiation of treatment after MI. The aim of the present study was to investigate to what extent early intervention with a mixed ET_A/ET_B receptor antagonist with higher affinity at the ET receptors (SB 209670) would also exert beneficial effects on postinfarction LV remodeling. After ligation of the left coronary artery, rats were randomized to treatment with SB 209670 (6.25 mg·kg⁻¹ SC b.i.d., n = 10) or vehicle (n = 12) for 26 days, starting 48 h after MI. Treatment with SB 209670 adversely affected the postinfarction remodeling process causing further dilatation of the LV (LV end-diastolic diameter: 10.4 ± 0.5 vs 9.1 ± 0.2 mm; LV end-systolic diameter: 8.5 ± 0.4 vs 7.2 ± 0.2 mm, P < 0.05). However, SB 209670 did not significantly affect infarct size, compensatory cardiac hypertrophy, nor the myocardial mRNA levels of procollagen type I and III, and prolyl 4-hydroxylase and lysyl oxidase, 2 important enzymes affecting collagen secretion, stability and functionality. In addition, SB 209670 had no significant effects on LV collagen cross-linking or extent of fibrosis. Thus, our data demonstrate that early intervention with a potent, mixed ET_A/ET_B receptor antagonist after MI may promote dilatation of the LV without significant alterations of infarct size and extracellular matrix composition. Our data support the notion that the timing of initiation of ET receptor antagonism after MI is critical and that potent ET receptor antagonists may be harmful during the first few days after MI. Received: 1 September 2001, Returned for revision: 13 September 2001, Revision received: 6 December 2001, Accepted: 21 December 2001     

高血压患者硝苯地平治疗前后血浆内皮素和降钙素基因相关肽的变化

目的观察硝苯地平降压治疗对血浆内皮素（ＥＴ）和降钙素基因相关肽（ＣＧＲＰ）水平的影响。方法３１例原发性高血压（ＥＨ）患者口服硝苯地平控释片４０ｍｇ／ｄ×１４，用放免法直接测定治疗前后的血浆ＥＴ和ＣＧＲＰ水平。结果ＥＨ患者血浆ＥＴ水平明显高于对照组（８５．６±２１．０ｖｓ４２．１±２０．３ｐｇ／ｍｌ，Ｐ＜０．００１）；ＣＧＲＰ水平明显低于对照组（２３．０±８．１ｖｓ５５．４±１７．８ｐｇ／ｍｌ，Ｐ＜０．００１）。舒张压与ＥＴ水平呈正相关（ｒ＝０．５３０２，Ｐ＜０．００５），ＥＴ与ＣＧＲＰ呈弱的负相关（ｒ＝０．３７０７，Ｐ＜０．００５）。治疗后，血压和ＥＴ水平明显下降（Ｐ均＜０．００１），ＣＧＲＰ水平显著增高（Ｐ＜０．００１）。结论硝苯地平是一种有效的降压药，它可通过调节ＥＨ时多种血管活性多肽之间的平衡关系，对器官保护具有重要作用     

G蛋白偶联受体激酶4对内皮素B型受体的异常调节在原发性高血压发生中的作用

目的探讨G蛋白偶联受体激酶4(G protein-coupled receptor kinase 4,GRK4)对内皮素B型受体(endothelin receptor B,ETB)的异常调节在原发性高血压中的作用及机制。方法选用12~14周龄,体质量300 g左右的雄性自发性高血压大鼠(spontaneously hypertensive rats,SHRs)及其对照鼠(Wistar-Kyoto,WKY)各10只,通过无创鼠尾测压仪测定血压,采用右肾上腺静脉插管灌注ETB受体特异性激动剂BQ3020后观察尿流速及尿钠排泄率,荧光定量PCR检测大鼠肾脏GRK4 mRNA水平,Western blot测定大鼠肾脏GRK4及ETB受体的蛋白表达差异,免疫共沉淀法检测ETB受体磷酸化情况,在动物水平观察高血压状态下ETB受体的功能情况。结果 ETB受体激动剂BQ3020对WKY大鼠有明显利尿排钠作用,且这种利尿排钠作用可以被ETB受体抑制剂BQ788阻断,但在SHR大鼠BQ3020的利尿排钠作用受损[尿流速:(11.23±2.16)vs(3.49±1.32),P<0.05];尿钠排泄率:[(1 551.43±393.47)vs(601.16±128.15),P<0.05];在SHR大鼠肾皮质GRK4的蛋白水平及mRNA水平均较WKY大鼠高[蛋白:(1.38±0.10)vs(0.85±0.07),P<0.05];mRNA:[(2.23±0.15)vs(0.78±0.16),P<0.05],SHR大鼠ETB受体总蛋白水平与WKY大鼠相比差异无统计学意义(P>0.05),但ETB受体磷酸化水平增高。结论 GRK4可能通过对内皮素B型受体的异常调节,参与了原发性高血压发生与发病。     

内皮素双受体拮抗剂在实验性急性肺栓塞中的应用研究

目的观察静脉内皮素双受体拮抗剂RO2610612在急性肺栓塞中的应用效果,研究内皮素与急性肺栓塞的关系。方法12只健康杂种犬随机分为对照组和实验组,每组6只。两组所有动物给予戊巴比妥静脉麻醉后分别于颈静脉插入热稀释漂浮导管连接生理监护仪;气管内插入气管插管连接呼吸描记器。采集栓塞前数据后于颈静脉注射自体血栓建立急性肺栓塞动物模型。实验组建立模型后1h开始持续静滴RO26106120.2mg/(kg.h),对照组同时输入等量生理盐水。对照组及实验组所有动物于栓塞前、栓塞后1,2,4,6h记录体、肺循环血流动力学指标、呼吸生理指标;取股动脉血3ml,采用放射免疫法测定动脉血内皮素-1水平,并测动脉血气。结果两组动物栓塞后较栓塞前血浆内皮素-1水平、肺动脉平均压、肺血管阻力、呼吸频率、动脉血二氧化碳分压和肺气道阻力显著性升高(P<0.05),心输出量、动脉血氧分压和肺动态顺应性显著性下降(P<0.05)。实验组于栓塞2h后肺动脉平均压、肺血管阻力、呼吸频率、肺气道阻力升高水平显著性低于同时期对照组(P<0.05),血浆内皮素-1水平、心输出量、和肺顺应性显著性高于对照组(P<0.05)。结论在急性肺栓塞病理过程中,内皮素参与了肺循环阻力升高与肺气道阻力升高和肺顺应性下降的形成。内皮素受体拮抗剂拮抗内皮素与其受体的结合,在急性肺栓塞中,可以减缓肺循环阻力、肺气道阻力的上升,因而可能成为急性肺栓塞临床治疗的新手段。     

A Reproducible and Translatable Model of Focal Ischemia in the Visual Cortex of Infant and Adult Marmoset Monkeys

Models of ischemic brain injury in the nonhuman primate (NHP) are advantageous for investigating mechanisms of central nervous system (CNS) injuries and testing of new therapeutic strategies. However, issues of reproducibility and survivability persist in NHP models of CNS injuries. Furthermore, there are currently no pediatric NHP models of ischemic brain injury. Therefore, we have developed a NHP model of cortical focal ischemia that is highly reproducible throughout life to enable better understanding of downstream consequences of injury. Posterior cerebral arterial occlusion was induced through intracortical injections of endothelin‐1 in adult (n = 5) and neonatal (n = 3) marmosets, followed by magnetic resonance imaging (MRI), histology and immunohistochemistry. MRI revealed tissue hyperintensity at the lesion site at 1–7 days followed by isointensity at 14–21 days. Peripheral macrophage and serum albumin infiltration was detected at 1 day, persisting at 21 days. The proportional loss of total V1 as a result of infarction was consistent in adults and neonates. Minor hemorrhagic transformation was detected at 21 days at the lesion core, while neovascularization was detected in neonates, but not in adults. We have developed a highly reproducible and survivable model of focal ischemia in the adult and neonatal marmoset primary visual cortex, demonstrating similar downstream anatomical and cellular pathology to those observed in post‐ischemic humans.     

Effect of Zataria multiflora Extract on Total and Differential White Blood Cell Count and Endothelin Level in Blood of Ovalbumin Sensitized Guinea Pigs

Objective: To investigate the effect of hydro-ethanolic extract of Zataria multiflora (Z. multiflora) on endothelin level, total and differential white blood cells (WBC) count of sensitized guinea pigs. Methods: Five groups of guinea pigs sensitized to ovalbumin (OA) were given drinking water alone (group S), drinking water containing three concentrations of Z. multiflora (0.2, 0.4 and 0.8 mg/mL as groups S+Z1, S+Z2 and S+Z3) and dexamethasone (group S+D), n=6 for each group. The endothelin levels as well as total and differential WBC count in blood of sensitized and control guinea pigs were evaluated using enzyme linked immunosorbent assay method, and hemocytometer and Wright-Giemsa''s staining of blood sample smear respectively. Results: Blood endothelin levels, total and most differential WBC count were increased but lymphocytes decreased in sensitized animals compared to controls (all P<0.01). In groups S+D, S+Z2 and S+Z3 endothelin level, total and differential WBC counts were significantly improved compared with group S (P<0.01). Although, all measured parameters in group S+Z1 was lower than group S+D (P<0.01), some parameters in group S+Z3 were greater than in group S+D (P<0.05 to P<0.01). Conclusion: The results showed an anti-inflammatory effect of Z. multiflora extract in sensitized guinea pigs, which may suggest a therapeutic potential for the plant on asthma.     

疏血通注射液联合纳洛酮治疗慢性肺心病急性加重期的临床研究

目的 探讨疏血通注射液联合纳洛酮治疗慢性肺心病急性加重期对血浆内皮素（ET-1）的影响。方法 采用回顾性与便利抽样研究方法,病例收治时间为2010年2月—2016年12月,选择在此期间在西安市五环集团职工医院诊治的慢性肺心病急性加重期患者122例,按照治疗方法的区别分为观察组与对照组各61例,对照组给予纳洛酮治疗,2 mg加入0.9% NaCl注射液100 mL中静滴,1次/d。观察组在对照组治疗的基础上给予疏血通注射6 mL加入0.9% NaCl注射液100 mL中静滴,1次/d。两组都治疗观察28 d。比较两组疗效、三尖瓣区最大返流速度（V_max）和肺动脉压（PAPs）及ET-1水平,同时比较两组凝血功能指标。结果 对照组总有效率为86.9%,观察组为98.4%,观察组显著高于对照组（P<0.05）。治疗后两组的V_max值、PAPs值与血浆ET-1含量均显著低于治疗前（P<0.05）,且观察组显著低于对照组（P<0.05）。治疗后两组的凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）与凝血酶时间（TT）值都显著高于治疗前（P<0.05）,且治疗后观察组显著高于对照组（P<0.05）。结论 疏血通注射液联合纳洛酮治疗慢性肺心病急性加重期能抑制血浆ET-1的表达,改善肺动脉压力,具有抗凝的作用,从而有利于提高治疗疗效。