人脐血细胞静脉移植对自发性高血压大鼠缺血再灌注脑损伤疗效及其机制探讨

目的探讨人脐血细胞(HUCBCs)静脉移植治疗自发性高血压(SHR)大鼠缺血再灌注脑损伤疗效及其相关机制。方法人脐血细胞体外分离、扩增并以4,6-2胺-2苯基吲哚(DAPi)标记。68只雄性SHR大鼠经线栓法建立大鼠大脑中动脉栓塞(MCAO)模型,并随机分为2组:治疗组和对照组。术后48h后经尾静脉治疗组注射1×106HUCBCs,对照组注射HUCBCs细胞培养基。于移植后3、14、28d,Bederson评分观察大鼠神经功能状况;图像分析法检测计算各组TTC染色脑梗死面积;荧光显微镜对治疗组脑组织DAPi染色阳性细胞计数;免疫组化法检测脑组织内脑源性神经营养因子(BDNF)染色阳性细胞数以及逆转录聚合链式反应(RT-PCR)检测移植后14、28d缺血侧脑组织BDNFmRNA表达水平。结果(1)移植后3d2组Bederson评分无显著差别,移植后14、28d治疗组显著低于对照组(P<0.05)。(2)移植后3d两组脑梗死面积无显著差别,移植后14、28d治疗组显著低于对照组(P<0.05)。(3)治疗组移植后3d梗死侧见少量DAPi阳性染色细胞,移植后14、28d梗死侧DAPi阳性染色细胞增加(P<0.05)...     

缺血-再灌注性急性肾功能衰竭时血清特异荧光研究

利用缺血-再灌注性急性肾功能衰竭家兔动物模型观测家兔缺血-再灌注不同时刻点血清的特异荧光。应用发光理论对缺血-再灌注性急性肾功能衰竭家兔血清的分子光谱及血清中的发光中心进行了分析。探讨了家兔缺血-再灌注性急性肾功能衰竭的发病进程与自由基、微循环及血清特异荧光的关系,阐述了产生血清特异荧光强度递增的可能机理。     

糖尿病性高血糖大鼠脑缺血再灌注后脑组织胶质细胞源性神经生长因子的表达及意义

目的探讨糖尿病性高血糖大鼠脑缺血再灌注后脑组织胶质细胞源性神经生长因子(GDNF)的表达及意义。方法41只Wistar大鼠随机分为正常对照组、假手术组、正常血糖脑缺血再灌注组(NIR)和糖尿病性高血糖脑缺血再灌注(DIR),用链脲佐菌素腹腔注射和线栓法分别诱发大鼠糖尿病和复制大脑中动脉缺血再灌注模型,应用免疫组化法检测再灌注6小时和24小时脑组织GD-NF蛋白的表达。结果大鼠脑缺血再灌注后GDNF主要表达于缺血周边区,NIR组GDNF表达在再灌注6小时组和24小时组均较假手术组和正常对照组表达明显增加(P<0.05);DIR组GDNF表达在再灌注6小时和组和24小组较NIR组表达明显下降(P<0.05)。结论大鼠脑缺血再灌注后脑组织GDNF表达增加可能是内源性保护机制;糖尿病性高血糖大鼠脑缺血再灌注后脑组织GDNF表达降低可能是糖尿病加重缺血损伤的机制之一。     

Cardioprotective effect of pump prime aprotinin in coronary artery bypass grafting

Background: Several studies have reported that high-dose aprotinin is cardioprotective in coronary surgery. The cardioprotective efficacy of low-dose aprotinin is less well defined. The present randomised study evaluated the cardioprotective and anti-inflammatory effects of pump prime aprotinin in patients undergoing coronary bypass surgery. Methods: Sixty-four male patients admitted for first-time elective coronary artery bypass surgery were randomised into control or aprotinin groups. Patients in the aprotinin group received 280 mg of aprotinin in the pump prime. Postoperative CK-MB release, leukocyte counts and hemodynamics were recorded. Perioperative myeloperoxidase, IL-6, IL-8 and IL-10 levels were measured in a subgroup of patients (15 patients in each group). Results: There were no significant differences between the groups in mechanical ventilation time and ICU and hospital stay. Postoperative bleeding was less serious in the aprotinin group than in the controls (742.0 ± 361.1 versus 885.2 ± 335.1 ml, p = 0.12) and CK-MB values were significantly lower (6 hrs, 35.5 ± 11.8 versus 44.5 ± 24.0 U/L; 24 hrs, 32.3 ± 25.0 versus 40.2 ± 26.8 U/L; 48 hrs, 15.9 ± 7.0 versus 24.7 ± 21.1 U/L; p = 0.041). Perioperative hemodynamics was similar in both groups. There was a tendency towards less vasopressor and inotropes use in the pump prime aprotinin group. There was no significant difference between groups in terms of perioperative myeloperoxidase, IL-6, IL-8 and IL-10 levels. Conclusions: Pump prime aprotinin marginally limits myocardial enzyme release, but fails to limit inflammatory responses after elective coronary surgery.     

Fish oil (polyunsaturated fatty acid) prevents ischemic-induced injury in the mammalian retina

The long-chain polyunsaturated omega-3 fatty acid docosahexaenoic (22:6n-3) acid (DHA) accumulates in rod outer segment disks and synaptic terminals. It has been thought to play an important role in disordering disk membranes and in providing an adequate environment for conformational rhodopsin changes and in modifying the activity of retinal enzymes. The decrease of DHA content in the retina has been shown to affect visual function in monkey. In rat retina, prolonged light exposure has produced reduction of DHA content in rod outer segments. The authors found that when DHA was administered before ischemia, it diminished pressure-induced retinal damage. The recovery of electroretinographic amplitudes in DHA-pretreated eyes was significantly greater than those in the control eyes after 4 hr of reperfusion. The histopathologic study of control eyes showed cell swelling and cell nuclei pyknosis in the inner nuclear layer after 4 hr of reperfusion and in TUNEL-positive cells in the inner and outer nuclear layers after 24-72 hr of reperfusion. The DHA pre-treated eyes had fewer pyknotic nuclei and vacuolated spaces in the inner nuclear layer and no TUNEL-positive cells for up to 72 hr of reperfusion. The precise role of the polyunsaturated n-3 fatty acid has not been identified in the retina and other tissues. Our findings showed that DHA probably prevented sensory retina from ischemic-reperfusion cell damage not only by inhibiting the formation of hydroxyl radicals, but also by reducing the non-NMDA responses or the inflammatory responses.     

脊髓内MAPK-ERK通路在心肌缺血再灌注损伤中的作用

目的：探讨脊髓内MAPK-ERK通路在幼年大鼠心肌缺血再灌注损伤中的作用。方法：将鞘内置管成功的60只Sprague-Dawley（SD）幼年雄性大鼠（80~100 g）随机分为3组：假手术组（n=10）、缺血再灌注组（n=25）和PD98059组（n=25）。假手术组实验前30 min鞘内注射5 μL DMSO,开胸后冠状动脉左前降支备线但不结扎;缺血再灌注组于实验前30 min鞘内注射5 μL DMSO,开胸后结扎冠状动脉左前降支上1/3段30 min,再灌注120 min;PD98059组于实验前30 min鞘内注射5 μL PD98059（5 μg）,余处理同缺血再灌注组。实验结束后取3组大鼠T1~T4段脊髓,免疫荧光法检测p-ERK表达情况。取3组大鼠心脏,分别检测其心肌梗死面积和缺血交界区心肌凋亡指数。结果：缺血再灌注组大鼠脊髓内p-ERK表达水平显著高于假手术组和PD98059组（P<0.05）;PD98059组心肌凋亡指数和心肌梗死面积均明显低于缺血再灌注组（P<0.05）,但仍高于假手术组（P<0.05）。结论：上胸段脊髓内MAPK-ERK通路在心肌缺血再灌注损伤中激活,阻断该通路可以产生明显的心肌保护作用。     

局灶性脑缺血再灌注认知功能变化的实验研究

目的 观察不同时相缺血再灌注的大脑中动脉闭塞大鼠模型认知功能的变化.方法 36只SD大鼠,雌雄各半,分为假手术组、缺血30 min再灌注组、缺血90 min再灌注组.采用Longa线栓法制成年SD大鼠大脑中动脉闭塞(MCAO)模型.通过观察大鼠神经行为学评分、术后14 d红四氮唑(TTC)染色、水迷宫及听觉事件相关电位(P300)对认知功能的变化进行研究.结果 缺血30 min再灌注组、缺血90 min再灌注组大鼠神经行为学评分都在2分以上.大鼠术后第14天,TTC染色的结果显示2组缺血再灌注组大鼠的脑组织均有梗死灶.在定位航行实验、空间探索实验和听觉事件相关电位(P300)中,缺血90 min再灌注组大鼠和假手术组、缺血30 min再灌注组大鼠都存在明显差异(P＜0.01).结论 局灶性脑缺血再灌注大鼠的认知功能下降并随缺血时间的不同呈正相关改变.     

莪达夏改善大鼠心肌缺血再灌注损伤的有效部位

目的探讨莪达夏改善大鼠心肌缺血再灌注损伤的有效部位。方法通过研究莪达夏不同提取部位对大鼠心肌缺血再灌注后的心肌组织中NO含量及一氧化氮合酶（NOS）、诱导性一氧化氮合酶（iNOS）活性的影响,明确其改善大鼠心肌缺血-再灌注损伤的有效部位。结果藏药莪达夏氯仿部位和乙酸乙酯部位可使心肌组织中NOS、iNOS活性和NO含量水平降低,且均低于模型组。结论莪达夏可能通过氯仿部位和乙酸乙酯部位降低心肌组织中的NOS、iNOS活性和NO含量,达到保护大鼠心肌缺血再灌注损伤的作用。     

熊果酸对大鼠局灶性脑缺血再灌注损伤的保护作用

目的:研究熊果酸对大鼠局灶性脑缺血再灌注损伤的保护作用并探讨其作用机制。方法:120只清洁级雄性SD大鼠随机分为假手术组、局灶性脑缺血再灌注模型组、熊果酸(20,40,80,120 mg·kg-1)治疗组,每组20只。采用颈内动脉线栓法制备大鼠局灶性脑缺血再灌注模型,术后通过尾静脉注射给药。6 h后,盲法行神经功能评分,测定脑梗死体积及脑组织含水量,测定血清中肌酸激酶(CK),乳酸脱氢酶(LDH),丙二醛(MDA)含量以及总抗氧化能力(T-AOC);检测脑组织中超氧化物歧化酶(SOD),谷胱甘肽过氧化物酶(GSH-Px),过氧化氢酶(CAT)活性及MDA含量;通过苏木精-伊红(HE)染色法观察脑组织病理形态学改变。结果:与假手术组比较,局灶性脑缺血再灌注模型组大鼠出现明显的行为障碍,血清中CK,LDH,MDA含量显著降低(P0.01),T-AOC显著降低(P0.01),脑梗死体积和脑组织含水量显著升高(P0.01),脑组织中SOD,GSH-Px,CAT活性显著升高(P0.01),并且脑组织出现明显的病理性改变;与脑缺血再灌注模型组相比,熊果酸(40~120 mg·kg-1)治疗组大鼠行为障碍显著好转(P0.05,P0.01),血清中CK,LDH,MDA含量显著降低(P0.05),T-AOC显著升高(P0.05,P0.01);熊果酸(80,120 mg·kg-1)治疗组脑梗死体积和脑组织含水量显著降低(P0.05,P0.01),脑组织中SOD,GSH-Px,CAT活性显著升高(P0.05,P0.01),MDA含量显著降低(P0.05);脑组织病理形态学改变明显减轻,其中以熊果酸120 mg·kg-1治疗组效果最为显著。结论:熊果酸对大鼠脑缺血再灌注损伤具有剂量依赖性的保护作用,该作用可能与熊果酸有效改善抗氧化酶系统活性、减轻自由基损伤有关。     

温阳通脉方对大鼠心肌缺血再灌注RISK通路机制研究

目的：观察温阳通脉方对缺血再灌注大鼠心肌的保护作用及其可能机制。方法将40只SD雄性大鼠随机分为假手术组、心肌缺血再灌注损伤组（IR组）、心肌缺血预适应组（IP组）、温阳通脉方组（WY组）。建立大鼠心肌缺血再灌注损伤（IR）模型及心肌缺血预适应（IP）模型。检测各组大鼠血清心肌坏死标记物肌钙蛋白T （cTnT）含量,免疫组化法检测心肌bax、bcl-2蛋白表达, western-blot检测akt、 p-akt表达。结果 WY组、 IP组血清cTnT含量低于IR组（P 〈0.05）,高于假手术组（P〈0.05）。 WY组、 IP组bax表达低于IR组（P〈0.05）。 WY组和IP组bcl-2、 akt蛋白表达高于IR组（P〈0.05）。 WY和IP组血清cT-nT含量及心肌bcl-2、 bax、 akt表达比较无统计学差异（P〉0.05）。结论温阳通脉方预处理具有心肌保护作用,其保护机制可能与激活akt通路,上调bcl-2,抑制bax蛋白表达有关。