蛋白激酶C和蛋白酪氨酸激酶活性对缺血再灌注心肌细胞凋亡影响的实验研究

为探讨缺血预适应（Ｉｓｃｈｅｍｉｃ Ｐｒｅｃｏｎｄｉｔｉｏｎｉｎｇ,ＩＰ）早期以及蛋白激酶Ｃ（Ｐｒｏｔｅｉｎ Ｋｉｎａｓｅ Ｃ,ＰＫＣ）及蛋白酷氨酸激酶（Ｐｅｏｔｅｉｎ Ｔｙｒｏｓｉｎｅ Ｋｉｎａｓｅ,ＰＴＫ）激动剂和抑制剂对缺血再灌注（Ｉ／Ｒ）心肌细胞凋亡的影响以及ＩＰ效能发挥通路中央ＰＫＣ和ＰＴＫ的关系。用ＴＵＮＥＬ法检测Ｉ／Ｒ心肌细胞凋亡。结果显示：１、ＩＰ早期能显著降低Ｉ／Ｒ心肌细胞凋亡（     

脑力智宝对PC12细胞缺血性损伤的保护作用

用ＮａＣＮ加缺糖造成的ＰＣ１２细胞缺血性损伤模型,研究脑力智宝含药血清对细胞的保护作用。并对所取含药血清时不同的给药次数,采血时间和含药血清加入量等实验方法进行了探讨。结果表明,单次给药后０．５、１．２、３ｈ所采集的含药血清不具有细胞保护作用,而两次给药（间隔２ｈ）后１ｈ,２ｈ的含药血清具有明显的保护作用。每日两次给经连续３．５ｄ（７次给药）各时间点的含药血清均有明显的细胞保护作用。血清加入量以５     

单纯缺血预处理对未成熟兔心脏的作用研究

目的 探讨缺血预处理（Ｉｓｃｈｅｍｉｃ Ｐｒｏｃｏｎｄｉｔｉｏｎｉｎｇ ＩＰＣ）对未成熟心脏全心缺血再灌注损伤的影响。方法 对经历５Ｍｉｎ缺血、１０Ｍｉｎ再灌注的幼兔（１４～２１天）心脏进行离体灌注,观察其在生理温度（３９℃）下接受３０Ｍｉｎ缺血、４０Ｍｉｎ再灌注的心肌酶释放、心肌能量及病理变化。结果 ＩＰＣ组全心缺血后心脏停跳持续时间显明延长（Ｐ〈０．０１）,心肌ＡＴＰ含量明显减少（Ｐ〈０．００     

Ischemic stress induces deposition of amyloid β immunoreactivity in human brain

The histoblot immunostaining technique for locating and characterizing amyloidogenic proteins was used to obtain information about the relationship of cerebral ischemia/hypoxia to the accumulation of amyloid protein (Aß). We investigated brains of 131 subjects (ages 25–94 years, mean 72 years). Three distribution patterns of A immunoreactivity were identified: (1) colocalization with diffuse and neuritic plaques of Alzheimer's disease (AD) and aging; (2) diffuse punctate deposits in the cerebral cortex in association with small vessel cerebral vascular disease; and (3) cerebral cortical accumulation localized to arterial boundary zones and other regions susceptible to ischemic/hypoxic injury designated stress-induced deposits (SID). SID were not identified in tissue sections by immunohistochemical, Congo red or Bielschowsky silver techniques; no histological abnormalities were present in adjacent formalin-fixed tissue sections. SID occurred in subjects with histories of cerebral ischemia, and severe orthostatic hypotension. There was also an association with aging in general and with the incidence of neuritic plaques specifically. These latter findings are consistent with the hypothesis that brain ischemia/hypoxia plays a role in the pathogenesis of AD.     

静脉滴注尼莫地平治疗急性缺血性脑梗死

发病72h内的急性缺血性脑梗死60例,分为2组。尼莫地平组30例(男性21例,女性9例;年龄59±s10a)。wk1.2给支持疗法(脱水剂,维生素C等)和尼莫地平2mg/d于5％葡萄糖液500ml内静脉滴注。wk3.4改用扩容、改善微循环,细胞活性药。wkl-4口服尼莫地平60mg.qn。对照组30例(男性23例,女性7例;年龄58±9a)。不给尼莫地平,其余同上。4wk后,前组神经功能缺损积分值较后组下降显著(P相似文献   

银杏叶提取物对兔心肌缺血再灌注损伤时中性粒细胞活化的影响

目的 观察兔心肌缺血再灌注前后ＰＭＮ（中性粒细胞）的活性变化过程。了解银杏叶提取物保护心肌是否与影响中性粒细胞活化作用有关。方法 取３０只日本大耳白兔随机均分为３组,假手术对照组、缺血再灌注组和实验用药组。用药方法：用自制的银杏叶提取物注射剂（总黄酮含量５ｍｇ／ｍｌ）５ｍｌ静滴给药。分别于冠脉结扎前和结扎缺血１ｈ后采血用布式显微镜观察白细胞活化状态的变化。检测白细胞表面粘附分子ＣＤ１１／ＣＤ１８表     

大鼠局灶性脑缺血神经细胞凋亡与坏死的研究

用凝胶电泳及原位末端标记研究大鼠脑缺血再灌流后神经元的凋亡与坏死。采用可逆性大脑中动脉阻塞２ 小时,再灌流０．５～４８ 小时,造成脑缺血再灌流模型（３０ 只）,用ＨＥ、原位末端标记（ＴＵＮＥＬ）和琼脂糖凝胶电泳观察神经元的改变。结果：缺血损伤区位于视前区、纹状体和皮质,再灌流０．５ 小时,视前区的缺血损伤区有较多的凋亡细胞,而皮质、纹状体仅有散在的凋亡细胞。再灌流３～６小时,凋亡细胞数量增多,并可见坏死细胞,１２小时达高峰,持续到２４ 小时,并可见凋亡细胞各种形态,凋亡细胞主要位于缺血损伤区内界,坏死细胞也增多。４８小时完全坏死区周围有成群的凋亡细胞。电泳显示涂片状背景上有明显的ＤＮＡ带。细胞凋亡参与缺血再灌流所致的神经元损伤,凋亡细胞与坏死细胞并存,细胞凋亡使梗塞区面积扩大。     

Role of reactive oxygen in phospholipase A2 activation by ischemia/reperfusion of the rat kidney

Purpose. To investigate the role of phospholipase A₂ (PLA₂) in reperfusion injury of the kidney in an in vivo animal model, renal mitochondrial PLA₂ activity was measured under three different conditions. Methods. Male Wistar rats (n = 72) anesthetized with pentobarbital underwent renal ischemia surgically for 45 min and were reperfused for the indicated time (renal ischemia/reperfusion). Treatments included reperfusion for various predetermined periods (phase 1), exposure to hyperbaric oxygen (phase 2), and administration of reactive oxygen species (ROS) scavenger (phase 3). Thereafter, each kidney was harvested, and mitochondrial PLA₂ activity was measured by a radioisotope technique. Results. Ischemia/reperfusion resulted in time-related PLA₂ activation in the renal mitochondria up to 48 h of reperfusion after renal ischemia. Renal mitochondrial PLA₂ activity was further augmented by hyperbaric oxygen exposure prior to reperfusion, whereas administration of the ROS scavengers suppressed mitochondrial PLA₂ activity. Conclusion. These data suggest that ROS may play an important role in the in vivo activation of PLA₂ associated with renal ischemia/reperfusion. Received for publication on July 6, 1998; accepted on November 30, 1998     

Effect of intracerebral norepinephrine depletion on outcome from severe forebrain ischemia in the rat

Manipulations of plasma catecholamine concentrations influence outcome from ischemic brain insults. It has been suggested that these effects are mediated by influences on brain catecholamine concentrations. This study examined whether major changes in brain norepinephrine concentrations can alter outcome from severe forebrain ischemia. Sprague-Dawley rats were administered 50 mg/kg i. p. N-(chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) or were left untreated (control). One week later, these rats were subjected to either 7 or 8 min of normothermic forebrain ischemia (bilateral carotid occlusion and MABP=30 mmHg) and allowed to recover for 4 days. Histologic damage was then evaluated. In other control and DSP-4-treated animals, hippocampal microdialysate norepinephrine concentrations were measured before, during and after 8 min of forebrain ischemia. Norepinephrine concentrations were also determined in brain homogenates from non-ischemic DSP-treated and control rats. A 95% depletion of norepinephrine was observed in brain homogenates from non-ischemic DSP-4-treated rats compared with control. During ischemia, microdialysate norepinephrine concentrations increased in control but not in DSP-4-treated rats (P=0.002). For plasma, intra-ischemic epinephrine concentrations increased 8-10-fold and returned to baseline values post-ischemia with no differences between groups. Plasma norepinephrine values remained unchanged in both groups. Histologic damage resulting from either 7 or 8 min of ischemia in hippocampal structures, caudoputamen, and neocortex was similar between DSP-4-treated and control groups. This study could not identify any effect of major changes in brain norepinephrine concentrations on ischemic brain damage. These data indicate that peripheral catecholamine effects on near-complete forebrain ischemic outcome are unlikely to be mediated by effects on central catecholamine concentrations.