人参二酵组皂甙对缺血-再灌注脑组织超微结构及NOS的影响

目的：研究人参二醇组皂甙（ＰＤＳ）对大鼠脑缺血－再灌注海马超微结构、皮层和海马一氧化氮合酶（ＮＯＳ）活性的影响。方法：双侧颈总动脉阻断和再灌注建立脑缺血－再灌流模型,电镜技术和ＮＡＤＰＨ－ｄ组织化学技术。结果：电镜观察可见,缺血３０ｍｉｎ再灌注２ｈ大鼠海马超微结构发生缺血性病理改变,ＰＤＳ对缺血脑组织病理变化有显著保护作用。ＮＡＤＰＨ－ｄ组织化学实验表明,脑缺血１５ｍｉｎ和再灌注２４ｈ后,皮层及海马ＮＯＳ阳性细胞数目显著增多,ＰＤＳ可显著抑制此增多。结论：ＰＤＳ可通过降低脑内ＮＯＳ的活性,减少脑缺血－再灌注过程中ＮＯ的产生,对缺血脑组织产生保护作用     

肾髓质诱导型一氧化氮合酶在动脉血压调控中的作用

本文通过慢性血液动力学实验,观察了肾髓质局部输入诱导型一氧化酶（ｉＮＯＳ）抑制剂ＡＧ（ａｍｉｎｏｇｕａｎｉｄｉｎｅ）对Ｄａｈｌ盐敏感大鼠（ＤＳ）、Ｄａｈｌ盐抵抗大鼠（ＤＲ）及ＳＤ（Ｓｐｒａｇｕｅ Ｄａｗｌｅｙ）大鼠动脉血压的影响,并测定了一氧化氮（ＮＯ）代谢终产物ＮＯ２及ＮＯ３含量（ＵＮＯＸ）、ｉＮＯＳ活性、肾功能以及血浆肾素活性（ＰＲＡ）。结果表明：ＡＧ能明显放大高盐（８％）引起的ＤＳ及ＳＤ大鼠     

人参二酶组皂甙对缺血—再灌注脑组织超微结构及NOS的影响

目的：研究人参二醇组皂甙（ＰＤＳ）对大鼠脑缺血－再灌注海马超微结构、皮层和海马一氧化氮合酶（ＤＮＯ）活性的影响。方法：双侧颈总动脉阻断和再灌注建立脑缺血－再灌流模型,电镜技术和ＮＡＤＰＨ－ｄ组织化学技术。结果：电镜观察可见,缺血３０ｍｉｎ再灌注２ｈ大鼠海马超微结构发生缺血性病理改变,ＰＤＳ对缺血脑组织病变化有显著保护作用。ＮＡＤＰＨ－ｄ组织化学实验表明,脑缺血１５ｍｉｎ和再灌注２４ｈ后,皮层海马Ｎ     

止血带休克时主动脉舒缩功能与一氧化氮合酶活性的关系

目的：为探讨止血带休克发生过程中血管舒缩功能的改变及意义,以及与血管一氧化氮（ＮＯ）产生的关系。方法：采用Ｒｏｓｅｎｔｈａｌ方法复制大鼠止血带休克（ＴｏＳ）模型,分别测定对照组和ＴｏＳ组大鼠血浆中,主动脉孵育液中亚硝酸盐（ＮＯ－２）含量及主动脉组织中ｃＧＭＰ含量,一氧化氮合酶（ＮＯＳ）活性,同时观察了主动脉血管环舒缩功能的改变。结果：ＴｏＳ大鼠离体主动脉环对去甲肾上腺素的反应性降低;其血浆和主动脉孵育液中ＮＯ－２明显增加;主动脉ｃＧＭＰ含量增多;主动脉血管总ＮＯＳ活性加强,其中主要是诱导型ＮＯＳ（ｉＮＯＳ）活性增加。结论：ＴｏＳ大鼠主动脉ＮＯＳ活性加强,产生ＮＯ增多,造成血管低反应性。     

内皮素-1前体基因反义寡核苷酸对正常和高血压大鼠血流动力学的影响

我们筛选出针对内皮素－１（ＥＴ－１）前体基因反义硫代寡核苷酸片断（ＥＴＡＳＯＤＮ）,已证明ＥＴＡＳＯＤＮ能显著抑制培养内皮细胞ＥＴ－１的生成,本应用该片断,对下沉和腹主动脉狭窄－高盐摄入型高血压大鼠侧脑室进行注射,记录注射前后血流动力学指标、注射后侧脑室周围组织中ＥＴ－１的含量及分布,ＥＴＡＳＯＤＮ对正常和高血压大鼠的影响,发现高血压大鼠脑干ＥＴ－１含量明显高于正常大鼠;ＥＴＡＳＯＤＮ能降低高血压     

肺血管EDNO及其合酶在大鼠低氧性肺动脉高压形成中的作用

本研究观察了低氧对大鼠肺组织和血管内皮一氧化氮合酶（ＮＯＳ）活性及内皮衍生一氧化氮（ＥＤＮＯ）依赖性舒张反应的影响,以及ＮＯＳ抑制剂（Ｌ－ＮＡＭＥ）对常氧和低氧大鼠肺组织和血管内皮ＮＯＳ活性及颈、肺动脉血压（ＣＡＰｓ、ｍＰＡＰ）的作用。结果表明常氧大鼠肺泡内无肌性血管内皮未见ＮＯＳ活性,其肺血管床对ＥＤＮＯ依赖性舒血管物质ＢＫ没有反应,注射Ｌ－ＮＡＭＥ后大鼠ｍＰＡＰ略有降低,ＣＡＰｓ有所升高。低氧大鼠肺泡内无肌性血管内皮显示ＮＯＳ活性,对ＢＫ的ＥＤＮＯ依赖性舒张反应呈剂量依赖性增大,注射Ｌ－ＮＡＭＥ使低氧大鼠ｍＰＡＰ显著降低（Ｐ＜０．０１）,ＣＡＰｓ显著升高（Ｐ＜０．０５）。提示肺血管ＥＤＮＯ及其合酶在维持正常成年大鼠肺循环低压低阻中的生理作用值得进一步探讨;低氧引起肺血管内皮ｅｃＮＯＳ活性增加和ＥＤＮＯ生成增多可能起到限制肺动脉压过度升高的调制作用,也可能对肺血管内皮产生毒性作用,反而促进肺动脉高压的发生和发展。     

内源性一氧化碳与一氧化氮在高血压发病中的相互作用 …

目的和方法：采用ＨＯ活性抑制剂诱导大鼠高血压模型,观察血压变化、主动脉ＨＯ和ＮＯＳ活性、ＣＯ和ＮＯ产生释放,并测定血浆和主动脉平滑肌组织中ｃＧＭＰ含量,以探讨内源性ＮＯ和ＣＯ在高血压发生机制中的作用及其相互关系。结果：大鼠应用ＨＯ抑制剂ＺｎＤＰＢＧ腹腔注射２周后,继续饲养到第４周出现持续而稳定的高血压,同时总ＮＯＳ（ｔＮＯＳ）和诱导型ＮＯＳ（ｉＮＯＳ）的活性分别增加４５．４％和７３．３％（均为Ｐ〉     

针刺抗脑缺血性神经元凋亡作用与机制的研究

本研究在肯定针刺抗缺血性神经元凋亡的基础上,进一步探讨针刺对内源性促凋亡因素及抑制凋亡因素的调整作用,寻找针刺对元保护作用的切入点及作用机制。结果表明：（１）针刺能减轻脑缺血导致的神经缺损行为异常,缩小梗塞面积;（２）ＰＩ荧光染色及ＴＵＮＥＬ染以显示：大鼠缺血皮层梗塞区有大量凋亡阳性信号细胞,电针后细胞凋亡受到明显抑制测定ＮＯ含量及观察ｃＮＯＳ和ｉＮＯＳ免疫活性显示：大鼠脑缺血－再灌注后脑内ＮＯ水     

CNTF对严重烫伤海马神经元损伤的保护作用

目的：观察大鼠体表严重伤后海马神经元的病理变化,探讨ＣＮＴＦ对其保护作用。方法：ＳＤ大鼠侧脑室埋管,制成３０％体表面积Ⅲ度烫伤模型,伤后３天,测定脑组织含水量,海马乳酸脱氢酶（ＬＤＨ）和一氧化氮（ＮＯ）的含量,做病理切片,尼氏染色。结果：大鼠严重烫伤后,脑组织含水量增加,海马出现明显的病理变化,尼氏小体减少或消失,胞体肿胀,ＬＤＨ和Ｎ煌含量增加,给予ＣＮＴＦ后,脑水肿、海马的病理变化有明显改善,并     

大鼠隔区一氧化氮合酶阳性神经元的分布和脑缺血后的变化

大鼠隔区一氧化氮合酶阳性神经元的分布和脑缺血后的变化ＤＩＳＴＲＩＢＵＴＩＯＮＡＮＤＩＳＣＨＥＭＩＡＩＮＤＵＣＥＤＣＨＡＮＧＥＳＯＦＮＩＴＲＩＣＯＸＩＤＥＳＹＮＴＨＡＳＥＰＯＳＩＴＩＶＥＮＥＵＲＯＮＳＩＮＴＨＥＳＥＰＴＡＬＡＲＥＡＯＦＲＡＴ关键词大鼠...     

大鼠脑血管痉挛时NO和ET—1变化及尼莫地平的影响

目的探讨蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)时脑组织一氧化氮(NO)和内皮素-1(ET-1)含量变化及尼莫地平(ND)对其影响。方法将135只Wistar大鼠随机均分为SAH组、ND处理组和假手术组,观察手术前后基底动脉管径,及24h内局部脑血流量(rCBF)、脑组织NO和ET-1含量动态改变,并行海马病理检查。结果SAH后rCBF明显而持续降低,基底动脉管径显著缩小;海马CAl区锥体细胞严重受损;脑组织NO和ET-1含量均在SAH后1～24h显著增加(P＜0．05～0．01)。ND处理后使上述异常变化均减轻。结论SAH后脑组织NO、ET-1增多可能参与了CVS所致脑损害过程,ND通过减轻CVS和拮抗脑组织NO及ET-1的病理性改变而发挥脑保护作用。     

Increase in receptor binding affinity for nimodipine in the rat brain with permanent occlusion of bilateral carotid arteries

The permanent occlusion of bilateral common carotid arteries (2VO) in rats has been shown to cause progressive and long-lasting cognitive deficits which may be due to impairment of memory retention and/or memory recall process. To clarify the function of voltage dependent calcium channels and the receptor binding of nimodipine by chronic cerebral ischemia, we examined specific (+)-[3H]PN 200-110 binding and the effect of oral administration of nimodipine in brain regions and hearts of rats, at 2 weeks to 4 months after permanent 2VO. There was no significant difference in either dissociation constant (Kd) or maximal number of binding sites (Bmax) for (+)-[3H]PN 200-110 in the cerebral cortex, hippocampus, corpus striatum and thalamus between 2VO and sham rats. In addition, in vitro inhibitory effect of nimodipine on cerebral cortical (+)-[3H]PN 200-110 binding in 2VO rats was similar to that in sham rats. Compared to control rats, oral administration of nimodipine to both 2VO and sham rats at 2 months after permanent 2VO brought about a significant increase in Kd values of specific (+)-[3H]PN 200-110 binding in the cerebral cortex, hippocampus, thalamus and myocardium, and the increase in Kd values was much larger in brain regions of 2VO rats than sham rats. However, the increase in Kd values in the myocardium did not differ between 2VO and sham rats. This observation suggests an increased in vivo binding affinity for nimodipine in chronic ischemic brain. In conclusion, the present study has shown that oral administration of nimodipine may cause a greater occupation in vivo of 1,4-dihydropyridine (DHP) calcium channel antagonist receptors in brains of permanent 2VO rats than in sham rats. Thus, nimodipine may be pharmacologically effective in preventing brain dysfunction due to cerebral ischemia in vivo.     

Nimodipine inhibits calcium-independent nitric oxide synthase activity in transient focal cerebral ischemia rats and cultured mouse astroglial cells

The effect of nimodipine on nitric oxide synthase (NOS) activities in brains in transient focal cerebral ischemia rats, in cultured mouse neurons and astroglial cells and bovine brain capillary endothelial cells (BCECs) was investigated. The administration of nimodipine (3 mg.kg(-1), p.o., twice a day, for 3 days) before middle cerebral artery (MCA) occlusion significantly reduced infarct size, decreased nitrite/nitrate (NOx) content and inhibited Ca2+-independent NOS activity in the infarct area. Nimodipine inhibited the Ca2+-independent NOS activity induced by lipopolysaccharide (LPS) + tumor necrosis factor alpha (TNF alpha) in mouse astroglial cells with an IC50 value of 0.036+/-0.003 mM and Ca2+-dependent NOS activity in mouse neurons with an IC50 value of 0.047+/-0.003 mM, but did not affect Ca2+-dependent NOS activity in BCECs. The inhibition of Ca2+-independent NOS activity by nimodipine in astroglial cells was competitive with respect to L-arginine. Nimodipine also inhibited the induction of Ca2+-independent NOS activity in vitro. These results suggest that nimodipine in addition to its cerebral vasodilating effect may protect brain from ischemic neuronal damage through modifying NOS activity.     

Pharmacological basis for the use of nimodipine in central nervous system disorders

Nimodipine, a Ca2+ antagonist with cerebrovasodilatory and anti-ischemic effects, binds to rat, guinea pig, and human brain membranes with high affinity (less than 1 nM). Only at higher concentrations has nimodipine been reported to block the release of some neurotransmitters and hormones from neuronal tissue. Nimodipine has no consistent effect on brain oxygen consumption or cortical ATP or phosphocreatine levels, although the ischemia-induced fall of brain ATP levels in gerbils or the lowering of intracellular brain pH in rabbits with focal cerebral ischemia were antagonized by the drug. In rats and baboons with middle cerebral artery occlusion, nimodipine was found to reduce neurological deficits without an increase in intracranial pressure or brain edema. Electrophysiological studies with nimodipine suggested a direct neuronal action. In rabbit dorsal root ganglion cells, concentrations as low as 20 nM were reported to block inward Ca2+ currents. Recent studies have suggested that nimodipine may also improve memory in brain-damaged or old rats, restore sensorimotor function and abnormal walking patterns of old rats, and accelerate acquisition of associative learning in aging rabbits. Blockade of age-related changes in Ca2+ fluxes in rat hippocampal neurones by nimodipine in vitro pointed to neuronal plasma membrane as the site of nimodipine action. The therapeutic usefulness of nimodipine appears not to be limited to cerebral ischemia, but may include dementia, age-related degenerative diseases, epilepsy, and ethanol intoxication.     

一氧化氮、内皮素-1对大鼠肢体缺血/再灌注后脑损伤的影响

目的: 研究一氧化氮(NO)和内皮素-1(ET-1)在大鼠肢体缺血/再灌注(LI/R)后脑损伤中的作用,探讨NO/ET-1平衡关系的变化对脑损伤的影响.方法: 在大鼠LI/R损伤模型上,应用NO合成前体物质L-精氨酸(L-Arg)、一氧化氮合酶(NOS)抑制剂氨基胍(AG)、ETA受体阻断剂BQl23进行干预,观察血浆 NO、ET-1、MDA、XOD、SOD、LDH及脑组织tNOS、iNOS、cNOS、NO、ET-1、MDA、XOD、MPO、 SOD的变化.结果: 与对照组比较,I/R组血浆MDA、XOD、LDH及脑组织MDA、XOD、MPO升高,SOD活性降低(P<0.01),脑组织tNOS和iNOS明显升高,而cNOS明显降低(P<0.01),I/R组血浆及脑组织NO、ET-1增加,NO/ET-1比值降低,脑损伤加重.应用L-Arg及BQ123后,血浆及脑组织NO/ET-1比值较I/R组升高,脑损伤减轻,应用AG后,NO/ET-1比值降低,脑损伤进一步加重.结论: 肢体缺血/再灌注后,一氧化氮与内皮素-l的比值降低时脑损伤加重.     

Reversibility of Nimodipine Binding to Brain in Transient Cerebral Ischemia

Using autoradiography, we have measured the in vivo binding of [3H]nimodipine to brain in a rat model of reversible cerebral ischemia. Ischemia was induced by simultaneous occlusion of the middle cerebral artery (MCA) and ipsilateral common carotid artery by microaneurysm clips. Rats were studied after 15 min of ischemia (ischemic group) or after 45 min of reperfusion following 15 min of ischemia (reperfused group). Regional cerebral blood flow (CBF) was determined autoradiographically using [14C]iodoantipyrine in both ischemic (n = 6) and reperfused (n = 6) groups. During ischemia blood flow in the territory of the MCA was depressed and recovered to normal only in the distal territory of the MCA following reperfusion. [3H]Nimodipine binding in the ischemic group (n = 12) was elevated in ischemic brain regions and declined significantly (p < 0.01) in these regions in the reperfused group (n = 11). The ratio of the volume of cortex showing increased binding to the total volume of the forebrain was 0.113 +/- 0.025 (mean +/- SD) in the ischemic group and declined to 0.080 +/- 0.027 following reperfusion (p < 0.005). In general, infarct was only observed in regions showing persistent elevation of nimodipine binding following reperfusion as determined by histology performed in a separate group of rats (n = 8) after 24 h of reperfusion. We conclude that increased nimodipine binding to ischemic tissue is initially reversible with prompt reestablishment of CBF and is a sensitive indicator of early and reversible ischemia-induced cerebral dysfunction.     

Neuroprotective Potential of Fasudil Mesylate in Brain Ischemia-Reperfusion Injury of Rats

We previously reported that inhibition of Rho-kinase (ROCK) by hydroxyl fasudil improves cognitive deficit and neuronal damage in rats with chronic cerebral ischemia (Huang et al., Cell Mol Neurobiol 28:757–768, 2008). In this study, fasudil mesylate (FM) was investigated for its neuroprotective potential in rats with ischemia following middle cerebral artery occlusion (MCAO) and reperfusion. The effect of fasudil mesylate was also studied in rat brain cortical and hippocampal slices treated with oxygen-glucose deprivation (OGD) injury. Gross anatomy showed that cerebral infarct size, measured with 2,3,5-triphenyltetrazolium chloride (TTC) staining, was significantly smaller in the FM-treated than in the non-FM-treated ischemic rats. In the brain regions vulnerable to ischemia of ischemic rats, fasudil mesylate was also found to significantly restore the enzyme protein expression level of endothelial nitric oxide synthase (eNOS), which was decreased in ischemia. However, it remarkably reduced the protein synthesis of inducible nitric oxide synthase (iNOS) that was induced by ischemia and reperfusion. In rat brain slices treated with OGD injury, fasudil mesylate increased the neuronal cell viability by 40% for cortex and by 61% for hippocampus, respectively. Finally, in the presence of OGD and fasudil mesylate, superoxide dismutase (SOD) activity was increased by 50% for cortex and by 58% for hippocampus, compared to OGD only group. In conclusion, our in vivo study showed that fasudil mesylate not only decreased neurological deficit but also reduced cerebral infarct size, possibly and at least partially by augmenting eNOS protein expression and inhibiting iNOS protein expression after ischemia-reperfusion. Xian-Ju Huang contributed equally to this article.     

Effect of total flavonoid in rabdosia rubescens on tolerant mice models under cerebral anoxia

ObjectiveTo study the protective effect of total flavonoid in rabdosia rubescens on BIT model by brain ischemic tolerance (hereinafter BIT) model of mice.MethodBIT model is used to block bilateral common carotid arteries and to copy BIT model of mice. After 10 min of transient ischemia for rats in preconditioning group, the mice in the nimodipine group and naoluotong capsule group were given the total flavonoid in rabdosia rubescens (300 mg/kg, 150 mg/kg, 75 mg/kg) for gavage, sham operation group, ischemia/reperfusion injury (hereinafter IRI) group and BIT group were fed with the same volume of 0.5% sodium carboxymethyl cellulose (CMC) once a day for 5 days. After administration for 1 h on day 5 (120 h), the rats in the other groups except for the sham operation group were treated with blood flow block for 30 min and reperfusion for 22 h. The serum NSE level were measured and the brain NO content and NOS activity changes was measured to observe the histopathological changes of brain tissue.ResultsBIT models of mice and in rats were both successfully replicated. The total flavonoid in rabdosia rubescens can decrease the mortality of mice, decrease serum NSE level, increase the content of NO and the activity of NOS in the brain tissue of mice, and improve the pathological damage of cortex and hippocampus of mice.ConclusionThe total flavonoid in rabdosia rubescens can stimulate an endogenous protective mechanism by inducing the release of low levels of cytokines NO and NOS, which reduces the release of serum NSE, relieves the brain tissue ischemia-reperfusion injury, and further improves the protection effect of ischemic preconditioning on brain injury. The damage of brain tissue ischemia and reperfusion, and further improve the ischemia Protective effect of preconditioning on brain injury.     

烟酰胺经调控p38MAPK信号通路对高血压脑出血大鼠的脑保护作用机制分析

摘要 目的：探讨烟酰胺经调控p38MAPK信号通路对高血压脑出血大鼠的脑保护作用机制。方法：选择48只SD大鼠,随机选择12只作为假手术组,其余36只进行高血压脑出血造模,对比4组大鼠的血肿体积、左扭转比率、神经功能变化、出血脑组织p-p38MAPK、p38MAPK蛋白表达、烟酰胺腺嘌呤二核苷酸、凋亡诱导因子含量及脑组织含水量。结果：与模型组相比,尼莫地平组、烟酰胺组的血肿体积明显缩小;与烟酰胺组相比,尼莫地平组的血肿体积明显缩小（P<0.05）;与干预前相比,干预后烟酰胺组、尼莫地平组的血肿体积明显缩小,模型组的血肿体积明显增多（P<0.05）。与模型组相比,假手术组、尼莫地平组、烟酰胺组的向左扭转比率、p-p38MAPK/p38MAPK、烟酰胺腺嘌呤二核苷酸明显较高,脑组织含水量、凋亡诱导因子含量明显较低;与烟酰胺组相比,尼莫地平组、假手术组的左扭转比率、p-p38MAPK/p38MAPK、烟酰胺腺嘌呤二核苷酸明显较高,脑组织含水量、凋亡诱导因子含量明显较低;与尼莫地平组相比,假手术组的左扭转比率、p-p38MAPK/p38MAPK、烟酰胺腺嘌呤二核苷酸明显较高,脑组织含水量、凋亡诱导因子含量明显较低（P<0.05）。结论：在高血压脑出血大鼠中,p38MAPK介导的细胞凋亡途径会加剧高血压脑出血的脑损伤,烟酰胺会经过抑制p38MAPK信号通路减轻高血压脑出血后的脑损伤。     

Nitric Oxide Participates in the Brain Ischemic Tolerance Induced by Intermittent Hypobaric Hypoxia in the Hippocampal CA1 Subfield in Rats

Previous studies have shown that intermittent hypobaric hypoxia (IH) preconditioning protected neurons survival from brain ischemia. However, the mechanism remains to be elucidated. The present study explored the role of nitric oxide (NO) in the process by measuring the expression of NO synthase (NOS) and NO levels. Male Wistar rats (100) were randomly assigned into four groups: sham group, IH?+?sham group, ischemia group and IH?+?ischemia group. Rats for IH preconditioning were exposed to hypobaric hypoxia mimicking 5000 m high-altitude (P_B?=?404 mmHg, PO₂?=?84 mmHg) 6 h/day, once daily for 28 days. Global brain ischemia was established by four-vessel occlusion that has been created by Pulsinelli. Rats were sacrificed at 7th day after the ischemia for neuropathological evaluation by thionin stain. In addition, the expression of neuronal NOS (nNOS), inducible NOS (iNOS), and NO content in the hippocampal CA1 subfield were measured at 2nd day and 7th day after the ischemia. Results revealed that global brain ischemia engendered delayed neuronal death (DND), both nNOS and iNOS expression up-regulated, and NO content increased in the hippocampal CA1 subfield. IH preconditioning reduced neuronal injury induced by the ischemia, and prevented the up-regulation of NOS expression and NO production. In addition, l-NAME?+?ischemia group was designed to detect whether depressing NO production could alleviate the DND. Pre-administration of l-NAME alleviated DND induced by the ischemia. These results suggest that IH preconditioning plays a protective role by inhibiting the over expression of NOS and NO content after brain ischemia.