辛伐他汀对兔脑血管痉挛中炎性反应的影响

目的探讨辛伐他汀对兔蛛网膜下腔出血（SAH）后脑血管痉挛（CVS）中炎性反应的影响。方法36只新西兰大白兔随机分为3组,每组12只。①对照组：给予常规饲养并枕大池二次注入等渗盐水;②sAH组：通过枕大池二次注血法建立SAH模型;③SAH＋辛伐他汀组：对SAH兔经胃灌注辛伐他汀5mg·kg^-1·d^-1,连续7d。在各组兔造模前后,行两次脑血管造影。第2次脑血管造影后1d,取基底动脉组织制作病理切片,分别于光镜和透射电镜下观察其显微及超微结构。行免疫荧光染色后,采用共聚焦显微镜观察基底动脉内皮细胞核转录因子-κB（NF—kB）表达量的变化,同时采用实时荧光定量PCR技术检测其细胞间黏附分子1（ICAM-1）mRNA的表达。结果①脑血管造影显示二次注血后,SAH组兔基底动脉出现明显的痉挛,管径变细,SAH组的管径为（0．68±0．09）mm,对照组为（0．87±0．06）mm,P〈0．05;而给予辛伐他汀后,痉挛减轻,SAH＋辛伐他汀组的管径为（0．77±0．08）mm,与SAH组管径比较,P〈0．05。SAH组兔基底动脉壁略有增厚,电镜显示平滑肌细胞内合成旺盛;而给予辛伐他汀预处理后,这些变化明显减轻。@SAH组兔基底动脉管壁内皮细胞内NF—κB表达高于对照组（156±9和84±8,P〈0．05）,而给予辛伐他汀后,NF—κB表达量降低（118±9）,与SAH组比较,P〈0．05。SAH组兔基底动脉组织ICAM-1mRNA的表达量高于对照组（0．843±0．029和0．673±0．011,P〈0．05）;给予辛伐他汀后,基底动脉ICAM-1mRNA的表达量低于SAH组（0．763±0．037）,与SAH组比较,P〈0．05。结论辛伐他汀可能通过抑制炎性反应从而预防SAH后CVS的发生,其抑制炎性反应,可能是通过NF—κB信号途径实现的。     

Experimental and clinical study on effect of endovascular dilation on symptomatic cerebral vasospasm

Objective To undertake animal experimentation and clinical study on the safety and efficacy of percutaneous transluminal angioplasty (PTA) and intraarterial papaverine (IAP) infusion for treatment of refractory symptomatic cerebral vasospasm (CVS). Methods In the experimental study, vasospasm was induced in rabbits by double injections of blood into the cisterna magMa, IAP infusion was given on either the 4th day or the 7th day after occurrence of subarachnoid hemorrhage (SAH), and then neurological observation, angiography, light and electron microscopy were done, In the clinical study, since September 1996, 22 patients with refractory symptomatic CVS involving 50 vascular territories received dilation therapy by PTA and IAP within 24 hours of clinical neurological deterioration. Results In the experimental study, all the rabbits except two in the ‘the 4th day‘ group showed angiographic dilation in all of the spastic basilar arteries, and neurological improvement; in the ‘the 7th day‘ group angiographic dilation appeared in 4 (57. 1% ) out of 7 rabbits. After 24 hours, 1 rabbit in each group had recurrence of neurological deficits and angiographic constriction. In the clinical study after aneurysm clipping or endovascular coil embolization was done, within 72 hours of SAH all patients underwent endovascular treatment: PTA alone in 3 cases, IAP alone in 14 cases, PTA and lAP in the remaining 5 cases. All vessel segments were dilated satisfactorily after endovascular treatment. Clinical improvement was significant in 13 eases,moderate in 7, minimal or none in 2; 2 cases died on the 7th day after endovascular dilation treatment. Conclusion Endovascular dilating techniques, namely, PTA, IAP and a combination of PTA and IAP, are safe and effective for treatment of symptomatic CVS refractory to medical therapy.     

米力农对兔蛛网膜下腔出血后脑血管痉挛的作用及其机制研究

目的探讨米力农对兔蛛网膜下腔出血(SAH)后脑血管痉挛的作用及其机制。方法取3个月龄日本大耳白兔32只,随机分为SAH组、对照组、米力农组及米力农+N-硝基-左旋精氨酸甲酯(L-NAME)组,共4组,每组8只。采用枕大池二次注入自体血建立SAH模型。向对照组兔枕大池内注入等渗盐水替代自体血,其他操作同SAH组。在SAH造模后30 min,对米力农组兔由耳源静脉注射米力农溶液5 ml(30μg/kg);米力农+L-NAME组,先经耳源静脉注射米力农溶液(30μg/kg),再注射L-NAME(30 mg/kg),共5 ml;对照组、SAH组注射等渗盐水5 ml。对4组兔均连续给药3 d,1次/d。术后第3天应用CT血管造影(CTA)和经颅多普勒超声(TCD)观察各组兔基底动脉的管径和血流速度。结果 TCD检查显示,对照组、SAH组、米力农组、米力农+L-NAME组基底动脉的平均血流速度分别为(19.4±1.8)、(32.7±4.2)、(17.8±1.8)及(33.2±7.2)cm/s;收缩期峰值流速分别为(27±5)、(45±4)、(29±3)及(44±4)cm/s。CTA检查显示,4组基底动脉管径分别为(1127±140)、(772±116)、(1113±101)及(802±91)μm。上述指标各组间比较,差异均有统计学意义,P<0.01。结论米力农对SAH后脑血管痉挛有缓解作用,其扩血管作用可能与L-NAME抑制一氧化氮合酶活性有关。     

CT血管造影评价兔基底动脉痉挛模型

目的探讨采用多层螺旋CT血管造影（multi-slices CT angiography，MSCTA）技术显示兔基底动脉，为兔脑血管痉挛（cerebralvasospasm，CVS）动物模型建立新的评价方法。方法取日本大耳白兔25只，分为对照组（5只）和蛛网膜下腔出血（subarachnoid hemorrhage，SAH）组（20只）。SAH组采用枕大池二次注血法制作兔脑基底动脉CVS模型，均经兔耳后中央静脉穿刺注射非离子型对比剂（碘海醇，含碘量300mg／m1），剂量按2．6ml／kg（体重）。采用高压注射器给药，注射速度0．4ml／s，延时15S开始扫描。SAH组于注血后1、4、7、11d，行2～5次基底动脉MSCTA。原始图像三维后处理技术采用容积重建（volume rendering，VR）。结果SAH组注血后1、4、7、11d基底动脉直径分别为（1．28±0．36）、（0．82±0．24）、（0．83±0．20）及（0．95±0．28）mm。VR法测得实验兔注血前基底动脉横径平均为（1．30±0．40）mm。CVS在注血后第1天出现，第4天达到高峰，第11天可见基底动脉痉挛有一定程度的缓解。结论MSCTA技术能够较理想地显示兔基底动脉，是评价活体动物CVS模型的可靠方法。     

红细胞生成素治疗兔脑血管痉挛及对核因子κB表达的影响

目的探讨红细胞生成素（EPO）对兔蛛网膜下腔出血（SAH）后迟发性脑血管痉挛（CVS）的疗效及其对核因子κB（NF-κB）表达的影响。方法取雄性新西兰白兔36只,随机分为对照组、SAH组和EPO治疗组,每组12只。采用枕大池二次注血SAH模型诱发迟发性CVS。EPO注射剂量为1000IU/kg,1次/8h;对照组和SAH组均给予EPO的溶剂（含人血清蛋白2.5mg/ml、氯化钠352mmol/L及蒸馏水）,以1ml/kg经腹腔注射,连续腹腔注射15次。造模后第5天处死动物,取基底动脉,采用HE染色测定基底动脉管腔横截面积,并用凝胶电泳迁移分析法检测NF-κB活性。结果①对照组、SAH组和EPO治疗组兔的基底动脉管腔横截面积分别为（0.412±0.034）、（0.210±0.018）和（0.342±0.030）mm2。SAH组与对照组比较,P〈0.01;EPO治疗组与SAH组比较,P〈0.01,与对照组比较,P〈0.05。②对照组、SAH组和EPO治疗组的NF-κB活性灰度值分别为：1.20±0.11、9.30±1.12和6.60±0.13,SAH组与对照组比较、EPO治疗组与对照组和SAH组比较,差异均有统计学意义（P〈0.01）。结论EPO能够缓解SAH后的迟发性CVS,并抑制SAH后血管中NF-κB的表达。     

吡咯烷二硫代氨基甲酸盐对兔脑血管痉挛的作用

目的观察吡咯烷二硫代氨基甲酸盐（PDTC）对兔蛛网膜下腔出血（SAH）后脑血管痉挛的影响及NF—κBp65、ICAM-1在基底动脉的表达。方法新西兰大白兔48只（雌雄不限）。随机分为对照组（8只）、SAH组（20只）及PDTC组（20只）。SAH组和PDTC组又分为SAH后1、3、5、7、14d亚组,每组4只。采用枕大池二次注血法制作SAH模型。PDTC组在第2次注血后即脑池内注射PDTC,0．25ml／次,2次／d,连续2d。观察基底动脉管径和厚度、病理形态学改变;免疫组化检测NF—κBp65、细胞间黏附分子1（ICAM-1）的表达。结果①SAH组在第3天开始出现基底动脉管径变细、管壁增厚,第7天最明显,与第1天比较,差异有统计学意义（P〈0．05,P〈0．01）;PDTC组仅第7天与第1天比较有差异（P〈0．05）。在第3、5、7天时,SAH组与对照组及PDTC组比较上述指标,差异均有统计学意义（P〈0．05,P〈0．01）;PDTC组与对照组比较,差异均无统计学意义。（2）PDTC组与SAH组同时间点比较,病理形态损害、炎性细胞浸润程度减轻。③SAH组在第3天开始出现NF—κBp6、ICAM—1表达,第7天达高峰。第3、5、7d（ICAM-1包括第14d）,SAH组表达量均明显高于对照组和PDTC组（P〈0．01）。PDTC组与对照组比较亦增高,P〈0．05。结论PDTC对SAH后迟发性脑血管痉挛具有一定的预防作用。通过抑制NF—κBp65、ICAM-1的表达可能是其机制之一。     

Involvement of imidazoline-preferring receptors in regulation of sympathetic tone

We examined the contribution of imidazoline-preferring receptors (IPR) and ₂-adrenoceptors at different levels of the central nervous system in the antihypertensive and sympathoinhibitory actions of rilmenidine in 2 conscious animal models, the spontaneously hypertensive rat (SHR) and the normotensive rabbit. In conscious SHRs, we compared the potency of rilmenidine and clonidine administered intravenously into the lateral cerebral ventricle, the cisterna magna, and into the subarachnoidal space of the thoracolumbar spinal cord. In SHRs, we found that rilmenidine was more potent and more effective by the intrathecal than the intracisternal route. By contrast, clonidine was most effective after administration into the cisterna magna. Intravenous administration of rilmenidine or clonidine induced dose-dependent and prolonged decreases in blood pressure and heart rate. Neither rilmenidine nor clonidine altered mean arterial pressure or heart rate when given into the lateral cerebral ventricle. These data suggest that in SHRs the spinal cord may be an important site for the antihypertensive action of rilmenidine. We therefore characterized the receptor type involved. We observed in conscious SHRs that intrathecal post-treatment with idazoxan, a mixed ₂-adrenoceptor and IPR antagonist, abolished the antihypertensive effect of rilmenidine, whereas 2-methoxyidazoxan, a selective ₂-adrenoceptor antagonist, caused only a partial reversal of the blood pressure effects of rilmenidine. These results suggest that rilmenidine acts mainly through IPR rather than ₂-adrenoceptors in the spinal cord. In view of these findings, we compared the hypotensive actions of rilmenidine and clonidine, administered into the lateral cerebral ventricle, the cisterna magna, and the subarachnoid space of the thoracolumbar spinal cord in conscious normotensive rabbits. Both drugs were less potent and effective when administered intrathecally than intracisternally. These experiments suggest that the hypotensive action of rilmenidine and clonidine in the rabbit is mediated through receptors mainly located in the brainstem. Further, we found that idazoxan reversed the hypotensive action of rilmenidine more readily than 2-methoxyidazoxan. Surprisingly, both idazoxan and 2-methoxyidazoxan completely reversed the depressor effects of clonidine. Therefore, in the rabbit, rilmenidine acts through IPR located in the brainstem and clonidine acts predominantly through ₂-adrenoceptors. In conclusion, our studies demonstrate that IPR are involved in the vasodepressor action of rilmenidine in both conscious SHRs and rabbits. However, although the main site of action of rilmenidine in SHRs may be located in the thoracolumbar spinal cord, in the rabbit it appears to be in the brainstem. The IPR selectivity for rilmenidine and the limited locations of this novel receptor may account for its good acceptability as a second-generation centrally acting antihypertensive agent.     

Attenuation of canine cerebral vasospasm after subarachnoid hemorrhage by protein kinase C inhibitors despite augmented phosphorylation of myosin light chain

The purpose of the present study is to assess the roles of protein kinase C (PKC) isoforms, especially PKC delta and alpha, and 20-kD myosin light chain (MLC(20)) phosphorylation in the mechanism of cerebral vasospasm following subarachnoid hemorrhage (SAH). We had shown that those PKC isoforms are involved in the development of cerebral vasospasm. Using PKC isoform-specific inhibitors in a 'two- hemorrhage' canine model, we examined changes in the development of cerebral vasospasm, translocation of PKC isoforms and MLC(20) phosphorylation level in canine basilar arteries. A PKC inhibitor (5 microM rottlerin for PKC delta or chelerythrine for PKC alpha) was injected into the cisterna magna on day 4 before the second hemorrhage. The treatment was continued daily until day 7. Rottlerin inhibited the initial phase of vasospasm and PKC delta translocation, but did not significantly inhibit PKC alpha translocation. Chelerythrine inhibited cerebral vasospasm, and the translocation of both PKC delta and alpha throughout the entire course of the study. Although cerebral vasospasm after SAH was inhibited by each PKC inhibitor, the MLC(20) phosphorylation level remained elevated as in the untreated hemorrhage-control study. We conclude that cerebral vasospasm following SAH depends on PKC delta and alpha, while the enhancement of MLC(20) phosphorylation contributes little to this form of vasospasm.     

罗格列酮对大鼠蛛网膜下腔出血后脑血管痉挛的保护作用

目的研究过氧化物酶体增殖物活化受体γ（PPAR-γ）激动剂-罗格列酮对大鼠蛛网膜下腔出血（SAH）模型脑血管痉挛的作用及对基底动脉Toll样受体4（TLR4）介导的炎性信号通路的影响。方法取SD雄性大鼠78只,应用抽签法随机分为对照组、SAH组及罗格列酮组,每组26只。采用枕大池二次注血法建立SAH模型。在2次注血前后30min,罗格列酮组大鼠经腹腔注射罗格列酮（3mg/kg,0．5mg/ml,二甲亚砜为溶剂）,给予SAH组大鼠等体积的二甲亚砜;对照组经枕大池注入等量等渗盐水,腹腔注射等体积二甲亚砜。于造模后第5天取基底动脉标本,HE染色观察管径和横截面积,免疫组化染色观察髓过氧化物酶（MPO）和细胞间黏附因子γ（ICAM-γ）的表达,Western blot检测TLR4蛋白的表达。结果对照组、SAH组、罗格列酮组大鼠的基底动脉的横截面积分别为（555084±4630）、（32139±3239）、（459694±4465）μ㎡,直径分别为（2604±14）、（1954±12）、（2374±12）μm。ICAM-1阳性细胞数分别为（0．5±0．2）、（4．7±0．7）、（2．5±0．6）个,MPO阳性细胞数分别为（0．9±0．3）、（17．9±2．6）、（6．5±1．3）个。TLR4蛋白的表达量分别为0．15±0．19、1．094±0．14、0．45±O．16。SAH组、罗格列酮组的上述指标与对照组比较差异有统计学意义,SAH组与罗格列酮组比较差异亦有统计学意义,P值均〈0．01。结论罗格列酮可能通过抑制TLR4信号通路途径,减轻SAH后基底动脉的炎性反应,缓解脑血管痉挛。     

Interactive role of protein kinase C-delta with rho-kinase in the development of cerebral vasospasm in a canine two-hemorrhage model

BACKGROUND: We previously reported that protein kinase C (PKC)-delta was initially translocated from the cytosol to the membrane fraction (on day 4), followed by PKC-alpha, with the progression of cerebral vasospasm after subarachnoid hemorrhage (SAH) on day 7. Rho/Rho-kinase pathways have also been proposed to be involved in the vasospasm. Thus we investigated the interactive role of Rho-kinase and PKC in the development of cerebral vasospasm after SAH. METHODS: The cerebral vasospasm was produced using a 'two-hemorrhage' canine model. The animals were treated with Y-27632, a Rho-kinase inhibitor, and rottlerin, a PKC-delta inhibitor, both injected into the cisterna magna. RESULTS: Y-27632 inhibited the vasospasm, 20-kDa myosin light chain (MLC20) phosphorylation, and PKC-delta translocation after the second injection of autologous blood on day 4. In contrast, Y-27632 did not affect the vasospasm on day 7. Rottlerin also inhibited the vasospasm on day 4, but had no effect on MLC20 phosphorylation and RhoA translocation. The vasospasm was accompanied with the phosphorylation of caldesmon (CaD), an actin-linked regulatory protein, which was strongly attenuated by Y-27632 and rottlerin. The application of PKC-delta to skinned strips of isolated canine basilar arteries caused a contraction and an increase in CaD phosphorylation. CONCLUSION: The development of cerebral vasospasm after SAH (on day 4) is caused by at least two mechanisms: one involves MLC20 phosphorylation mediated by the inhibition of MLC20 phosphatase by Rho-kinase, and the other CaD phosphorylation mediated by the activation of PKC-delta by Rho-kinase, which results in the alleviation of the inhibition by CaD of myosin Mg2+-ATPase activity.     

Gene transfer of calcitonin gene-related peptide prevents vasoconstriction after subarachnoid hemorrhage

We sought to determine whether adenovirus-mediated gene transfer in vivo of calcitonin gene-related peptide (CGRP), a potent vasodilator, ameliorates cerebral vasoconstriction after experimental subarachnoid hemorrhage (SAH). Arterial blood was injected into the cisterna magna of rabbits to mimic SAH 5 days after injection of AdRSVCGRP (8x10(8) pfu), AdRSVbetagal (control virus), or vehicle. After injection of AdRSVCGRP, there was a 400-fold increase in CGRP in cerebrospinal fluid. Contraction of the basilar artery to serotonin in vitro was greater in rabbits after SAH than after injection of artificial cerebrospinal fluid (P<0.001). Contraction to serotonin was less in rabbits with SAH after AdRSVCGRP than after AdRSVbetagal or vehicle (P:<0.02). Basal diameter of the basilar artery before SAH (measured with digital subtraction angiogram) was 13% greater in rabbits treated with AdRSVCGRP than in rabbits treated with vehicle or AdRSVbetagal (P:<0.005). In rabbits treated with vehicle or AdRSVbetagal, arterial diameter after SAH was 25+/-3% smaller than before SAH (P<0.0005). In rabbits treated with AdRSVCGRP, arterial diameter was similar before and after SAH and was reduced by 19+/-3% (P<0.01) after intracisternal injection of CGRP-(8-37) (0.5 nmol/kg), a CGRP(1) receptor antagonist. To determine whether gene transfer of CGRP after SAH may prevent cerebral vasoconstriction, we constructed a virus with a cytomegalovirus (CMV) promoter, which results in rapid expression of the transgene product. Treatment of rabbits with AdCMVCGRP after experimental SAH prevented constriction of the basilar artery 2 days after SAH. Thus, gene transfer of CGRP prevents cerebral vasoconstriction in vivo after experimental SAH.     

尼莫地平对兔蛛网膜下腔出血后症状性脑血管痉挛的影响

目的探讨尼莫地平对兔蛛网膜下腔出血（SAH）后症状性脑血管痉挛的影响。方法建立症状性脑血管痉挛动物模型，SAH＋尼莫地平组静脉内应用尼莫地平。观察对比神经功能缺损症状改善、血液流变学及电镜结果。结果SAH＋尼莫地平组随着尼莫地平的应用,神经功能缺损症状逐渐好转、血液流变学得到改善、透射电镜见基底动脉病理改变较SAH组减轻。结论SAH后早期应用尼莫地平对症状性脑血管痉挛具有明显的改善作用。     

Direct measurement of myocardial free radical generation in an in vivo model: effects of postischemic reperfusion and treatment with human recombinant superoxide dismutase.

OBJECTIVES. The purpose of this study was to determine whether postischemic reperfusion of the heart in living rabbits induces a burst of oxygen free radical generation that can be attenuated by recombinant human superoxide dismutase administered at the moment of reflow. BACKGROUND. This phenomenon was previously demonstrated in crystalloid perfused, globally ischemic rabbit hearts. METHODS. Thirty-two open chest rabbits were assigned to one of four groups of eight animals each: Group I (control animals), no coronary artery occlusion; Group II, 30 min of circumflex marginal coronary artery occlusion without reperfusion; Group III, 30 min of coronary occlusion followed by 60 s of reperfusion, and Group IV, 30 min of coronary occlusion followed by treatment with recombinant human superoxide dismutase (a 20-mg/kg body weight bolus 90 s before reperfusion and a 0.17-mg/kg infusion during 60 s of reperfusion). Full thickness biopsy specimens taken from the ischemic region were then rapidly freeze clamped and electron paramagnetic resonance spectroscopy was performed at 77 degrees K. RESULTS. Three radical signals similar to those previously identified in the isolated, crystalloid perfused rabbit heart were observed: an isotropic signal with g = 2.004 suggestive of a semiquinone, an anisotropic signal with g parallel = 2.033 and g perpendicular = 2.005 suggestive of an oxygen-centered alkyl peroxy radical, and a triplet with g = 2.000 and aN = 24 G suggestive of a nitrogen-centered radical. In addition, a fourth signal consistent with an iron-sulfur center was seen. The oxygen-centered free radical concentration during normal perfusion (Group I) was 1.8 +/- 0.8 mumol compared with 4.4 +/- 0.9 mumol after 30 min of regional ischemia without reperfusion (Group II) and 13.0 +/- 2.5 mumol after 60 s of reperfusion (Group III) (p < 0.05 among all three groups). In contrast, superoxide dismutase treated-rabbits (Group IV) demonstrated a peak oxygen radical concentration of only 5.9 +/- 1.2 mumol (p < 0.05 vs. Group III). CONCLUSIONS. This study demonstrates that reperfusion after regional myocardial ischemia in the intact rabbit is associated with a burst of oxygen-centered free radicals. The magnitude of this burst is greater than that seen after a comparable duration of global ischemia in the isolated, buffer-perfused rabbit heart preparation and is significantly reduced by superoxide dismutase administration begun just before reflow.     

Randomized,controlled trial of antioxidant vitamins and cardioprotective diet on hyperlipidemia,oxidative stress,and development of experimental atherosclerosis: The diet and antioxidant trial on atherosclerosis (DATA)

Summary The effects of administration of guava and papaya fruit (100 g/day), vegetables, and mustard oil (5 g/day) (group A); antioxidant vitamins C (50 mg/day) and E (30 mg/day) plus betacarotene (10 mg/day) (group B); a high-fat (5–10 g/day) (group C); or a low-fat (4–5 g/day) diet (group D) were compared over 24 diet weeks in a randomized fashion, while all groups of rabbits (five in each of four groups) received a hydrogenated fat diet (5–10 g/day) for a period of 36 weeks. After 12 weeks on the high-fat diet, each group of rabbits had an increase in blood lipoproteins. The fruit and vegetable-enriched prudent diet (group A) caused a significant decline in blood lipids at 24 and 36 weeks, whereas the lipid levels increased significantly in groups C and D. Group A also had a significant rise in vitamin E (2.1 Umol/l), C (10.5 Umol/l), A (0.66 Umol/l), and carotene (0.08 Umol/l) and a decrease in lipid peroxides (0.34 nmol/ml at 36 weeks, whereas the levels were unchanged in groups C and D. Group B rabbits had a significant and greater increase than group A in plasma vitamins E, C, A, and carotene; a rise in HDL cholesterol; and a greater decrease in lipid peroxides after 24 and 36 weeks of treatment. After stimulation of lipid peroxidation in all rabbits, 3 of 5 group C and 2 of 5 group D rabbits died due to coronary thrombosis, whereas in groups A and B there were no deaths, indicating that antioxidant therapy can provide protection against lipid peroxidation and free radical generation. Aortic lipids and sudanophilia, indicating atherosclerosis, were significantly higher in groups C and D than in groups A and B. Fatty streaks and atheromatous and fibrous plaques were noted in all the rabbits in groups C and D. Intimal fibrosis and medial degeneration were also present in the group C rabbits. While group A (36.4±4.4 µm) and group B (37.1±4.2 µm) rabbits had minimal coronary artery plaque sizes, group C (75.4±10.6 µm) and group D rabbits (69.5±6.2 µm) had significantly greater plaque sizes. Aortic plaque sizes were also greater in groups C and D than in groups A and B. It is possible that combined therapy with antioxidant vitamins C, E, and carotene, and a diet rich in antioxidants, could independently inhibit free radical generation and the development of atherosclerosis.     

Effects of blockade of cerebral lymphatic drainage on regional cerebral blood flow and brain edema after subarachnoid hemorrhage

The study was designed to observe the influence of blockade of cerebral lymphatic drainage on the regional cerebral blood flow (rCBF) and brain edema after experimental subarachnoid hemorrhage (SAH). Wistar rats were divided into non-SAH, SAH, and SAH plus cervical lymphatic blockade (SAH + CLB) groups. Autologous arterial hemolysate was injected into rat's cisterna magna to induce SAH. The rCBF was recorded continuously by a laser Doppler flowmeter. Intracranial pressure (ICP) was also monitored. After 24 hours and 72 hours of SAH, the rats were sacrificed and the brain was harvested for water content detection. It was found that there was no obvious change of rCBF and brain water content during the experiment in non-SAH group. An immediate and persistent drop in rCBF was found in SAH group. The drop in rCBF was more obvious in SAH + CLB group. CLB also worsened the SAH-induced increase in ICP. The brain water content 24 hours and 72 hours after induction of SAH in SAH group increased significantly. CLB led to a further increase of brain water content. In conclusion, blockade of cerebral lymphatic drainage pathway deteriorates the secondary cerebral ischemia and brain edema after SAH.     

Zinc protoporphyrin aggravates cerebral ischemic injury following experimental subarachnoid hemorrhage

This study was aimed to evaluate the influence of an antagonist of heme oxygenase, zinc protoporphyrin IX (ZnPPIX), on the production of endogenous carbon monoxide (CO) and the secondary cerebral injury after subarachnoid hemorrhage (SAH). Wistar rats were divided into non-SAH, SAH, and ZnPPIX groups. Autologus arterial hemolysate was injected into rat cisterna magna to induce SAH. CO and cyclic guanosine monophosphate (cGMP) levels in the brain, and lactate dehydrogenase (LDH) activity in serum were determined 24 hours and 72 hours after cisternal injection. It was found that 24 hours and 72 hours after SAH, the CO contents in SAH group were increased by 20.76% and 37.36%, respectively. CO content in ZnPPIX group was statistically lower than that in SAH group. No obvious change of cGMP content in SAH group was found. However, cGMP content in ZnPPIX group was lower than that in SAH group. Serum LDH activity increased significantly after induction of SAH. LDH activity in ZnPPIX group increased to a greater extent. It was concluded that ZnPPIX aggravates the cerebral injury secondary to experimental SAH by inhibiting the production of endogenous CO. The activation of HO/CO pathway is an intrinsic protective mechanism against cerebral ischemic injury after SAH.     

Expression of the receptors of VEGF and the influence of extract of Ginkgo biloba after cisternal injection of autologus arterial hemolysate in rats

The study was aimed to investigate the alterations of vascular endothelial growth factor (VEGF) receptors and the influence of extract of Ginkgo biloba (EGb) after subarachnoid hemorrhage (SAH). Wistar rats were divided into non-SAH, SAH, vehicle, EGb1 (lower dose), and EGb2 (higher dose) groups. Autologus arterial hemolysate was injected into cisterna magna to induce SAH. The non-SAH rats received cisternal injection of saline instead. Rats underwent RT-PCR determination of one of the VEGF receptors flt-1mRNA, and immunohistochemistry for VEGF receptors Flt-1 and Flk-1. The results revealed that there was only slight expression of flt-1mRNA in the brain tissue in non-SAH rats. The expression in SAH group was enhanced 24 hours and 72 hours after cisternal injection. No Flt-1 and Flk-1 positive cell was observed in the brain in non-SAH group. A good few Flt-1 and Flk-1 positive cells were found in cortex and other regions of the brain in SAH group. The expression of flt-1mRNA, Flt-1 and Flk-1 proteins were increased by the use of two doses of EGb. It was concluded that the up-regulated expression of the two kinds of VEGF receptors may be an intrinsic protective mechanism in the process of SAH, which can be enhanced by EGb.     

Melatonin decreases mortality following severe subarachnoid hemorrhage

Abstract:  Aneurysmal subarachnoid hemorrhage (SAH) is a devastating disease that is associated with significant morbidity and mortality. There is substantial evidence to suggest that oxidative stress is significant in the development of acute brain injury following SAH. Melatonin is a strong antioxidant that has low toxicity and easily passes through the blood–brain barrier. Previous studies have shown that melatonin provides neuroprotection in animal models of ischemic stroke. This study hypothesizes that melatonin will provide neuroprotection when administered 2 hr after SAH. The filament perforation model of SAH was performed in male Sprague–Dawley rats weighing between 300 and 380 g. Melatonin (15 or 150 mg/kg), or vehicle was given via intraperitoneal injection 2 hr after SAH. Mortality and neurologic deficits were assessed 24 hr after SAH. A significant reduction in 24-hr mortality was seen following treatment with high dose melatonin. There was no improvement in neurologic scores with treatment. Brain water content and lipid peroxidation were measured following the administration of high dose melatonin to identify a mechanism for the increased survival. High dose melatonin tended to reduce brain water content following SAH, but had no effect on the lipid peroxidation of brain samples. Large doses of melatonin significantly reduces mortality and brain water content in rats following SAH through a mechanism unrelated to oxidative stress.     

脑红蛋白对蛛网膜下腔出血大鼠早期脑损伤的保护作用

目的探讨脑红蛋白（NGB）对蛛网膜下腔出血（SAH）大鼠早期脑损伤的保护作用。方法将60只清洁级sD大鼠随机分为4组：正常组、假手术组、SAH组、治疗组（SAH＋腹腔注射氯化血红素）组。除SAH组30只外,其余每组10只大鼠。采用枕大池单次注血法建立大鼠SAH模型。采用免疫组化法和图像分析技术观测SAH后,不同时间大脑皮质颞叶的NGB免疫组化反应及平均吸光度A值;采用干湿法测量脑含水量,原位细胞凋亡检测法（TUNEL）检测颞叶神经元凋亡情况。结果①正常组和SAH后24h组平均吸光度4值分别是0．133±0．021和0．236±0．028：②sAH后颞叶皮质NGB阳性反应细胞迅速增加,24h达高峰,随后逐渐减少;③SAH组脑含水量为（77．5±0．4）％,治疗组脑含水量为（76．5±0．6）％,治疗组脑含水量较SAH组减少,差异有统计学意义（P〈0．05）;④治疗组和SAH组脑颞叶神经元凋亡程度为（9．8±2．4）％、（18．5±2．3）％。治疗组脑皮质神经元凋亡程度较SAH组降低（P〈0．05）。结论SAH后大鼠大脑皮质NGB阳性反应细胞呈动态变化。早期给予NGB能减少大鼠SAH模型的皮质神经元凋亡,降低脑水肿程度,具有明显的脑保护作用。     

抑制ERK1/2可减轻蛛网膜下腔出血大鼠脑水肿和下调基质金属蛋白酶-9表达

目的 研究细胞外信号调节激酶1/2(extracellular signal-regulated kinase1/2,ERK1/2)通路抑制剂U0126对蛛网膜下腔出血(subarachnoid hemorrhage,SAH)大鼠脑组织基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9...