西维来司钠对大鼠脑缺血再灌注后梗死体积、TNF-α和ICAM-1表达的影响

目的 观察两维来司钠对大鼠脑缺血再灌注后脑梗死体积及缺血脑组织TNF-α、ICAM-1表达的影响.方法 雄性Wismr大鼠随机分为假手术组、盐水对照组及药物组(200mg/kg).线栓法制作大鼠大脑中动脉闭塞再灌注模型.采用Trc染色方法测定脑缺血2h冉灌注0h、1h、4h、6h、8h、10h给药后各组脑梗死体积;应用RT-PCR方法检测脑缺血2h再灌注22h后缺血脑组织TNF-α、ICAM-1 mRNA的相对含鼍.结果 与对照组比较,再灌流0、1、4、6h后药物组脑梗死体积明减减小(P＜0.05);再灌注8h、10h组脑梗死体积减小,但无统计学意义(P＞0.05).再灌流22h后,药物组缺血脑组织中TNF-α和ICAM-1 mRNA表达明显下降(P＜0.05).结论 西维来司钠可明显减少脑缺血再灌注后梗死体积,降低TNF-α与ICAM-1 mRNA表达,发挥脑保护作用.     

亚低温对大鼠缺血再灌注后脑梗死体积和神经功能及ICAM-1的影响

目的研究亚低温对缺血脑组织的保护作用及对缺血区炎症反应的影响。方法制作大鼠大脑中动脉脑缺血模型,观察亚低温治疗对大鼠脑梗死灶体积、神经功能和缺血脑组织细胞间黏附分子-1(ICAM-1)表达的影响。结果亚低温组和常温组大鼠脑梗死体积占全脑体积的百分比分别为(22.95±2.69)和(30.83±2.67),神经功能评分分别为(1.43±0.25)和(1.97±0.30)分,ICAM-1表达的阳性血管数分别为(29.04±4.59)和(51.94±5.93),差异均有显著性意义。结论亚低温对缺血脑组织具有保护作用,对炎症级联反应的抑制是其发挥脑保护作用的重要机制之一。     

促红细胞生成素对大鼠局灶性脑缺血再灌注后梗死体积和脑组织水肿的影响

目的 探讨促红细胞生成素(EPO)对大鼠脑缺血再灌注损伤的保护作用。方法 采用阻断大鼠一侧大脑中动脉(MCA)血流2小时,再灌注48小时制成局灶性脑缺血模型。于再灌注开始前,治疗组经腹腔注入EPO(3000 U/Kg);缺血组和假手术组给予生理盐水腹腔注射,48小时后断头取脑。制作 HE切片;以2％氯化-2,3,5三苯基四氮唑(TFC)对脑片进行染色;经图像分析仪计算梗死体积占全脑体积的百分比;同时用干湿重法测定脑组织的含水量。结果 与对照组相比,治疗组海马 CA_1区神经细胞减少(25.7±1.16)％,缺血组减少(31.2±1.49)％;治疗组与缺血组比较有显著性差异(P<0.01)。治疗组脑梗死体积比缺血组明显缩小(P<0.01)。治疗组脑组织含水量比缺血组明显减少(P<0.01)。结论 EPO能够显著降低脑组织含水量,抑制脑水肿,缩小脑梗死体积及减少神经细胞坏死,对脑缺血再灌注损伤有良好的保护作用。     

β-七叶皂甙钠对大鼠局灶性脑缺血再灌注后NF-κB、ICAM-1、VCAM-1表达的影响

目的 探讨大鼠局灶性脑缺血再灌注脑组织缺血区不同时间点NF-κB、ICAM-1、VCAM-1蛋白表达的变化,及β-七叶皂甙钠干预效果.方法 采用大鼠大脑中动脉闭塞法(MCAO)制作局灶性脑缺血再灌注模型,用免疫组织化学方法观察大鼠脑缺血再灌注不同时间段,NF-κB、ICAM-1、VCAM-1蛋白的表达.并在大鼠于脑缺血前24h、1h及再灌注即刻分别腹腔给予β-七叶皂甙钠5mg/kg,2h MCAO,再灌注24h、48h后取脑,运用TTC染色测算脑梗死体积,免疫组化染色检测NF-κB、ICAM-1、VCAM-1蛋白表达,分析β-七叶皂甙钠的干预效应.结果 (1)脑缺血后缺血区脑组织NF-κB及ICAM-1、VCAM-1表达均增加,NF-κB于再灌注后12～24h表达达高峰,ICAM-1于再灌注后24h表达达高峰,VCAM-1于再灌注后24～48h表达达高峰.(2)NF-κB的表达与血管内皮ICAM-1、VCAM-1的表达呈正相关.(3)β-七叶皂甙钠能显著降低脑缺血再灌注后24h和48h缺血区NF-κB、ICAM-1及VCAM-1的表达增加.(4)β-七叶皂甙钠能明显减轻脑缺血再灌注后的脑组织损伤,再灌注24h脑梗死体积减少41.8%.结论 (1)脑缺血再灌注后NF-κB、ICAM-1、VCAM-1大量表达,这可能是脑缺血再灌注损伤机制之一.(2)脑缺血后NF-κB的活化可能与微血管内皮细胞ICAM-1、VCAM-1蛋白表达调控有关.(3)β-七叶皂甙钠能够减轻脑缺血后的脑组织损伤,有神经保护作用.     

糖尿病大鼠缺血再灌注脑组织NF-κB和ICAM-1的表达及意义

目的观察糖尿病大鼠缺血再灌注脑组织核转录因子(NF-κBp65)和细胞间粘附因子(ICAM-1)表达及意义。方法将89只Wistar大鼠随机分为对照组、假手术组、正常血糖缺血再灌注组(nIR)和糖尿病缺血再灌注组(dIR),观察时间点为再灌注0、6、12、24h,每个时间点各5只,用小剂量链脲佐菌素(STZ)腹腔注射诱发形成糖尿病大鼠模型,采用线栓法复制大鼠大脑中动脉闭塞再灌注模型,应用免疫组化的方法测定NF-κBp65和ICAM-1的表达水平。结果dIR组和nIR组NF-κBp65和ICAM-1主要表达于缺血周边区,dIR组再灌注0、6、12、24h NF-κBp65阳性细胞百分率分别为(24.7±4.2)、(53.4±8.0)、(72.4±7.2)、(60.7±5.0)%,与nIR组同一时间点比较差异有显著性(P<0.05);dIR组再灌注0、6、12、24h ICAM-1阳性微血管数分别为(0.8±0.8)、(2.4±1.6)、(5.1±2.1)、(3.6±1.6)条/8个400倍视野,与nIR组同一时间点比较0h组之间差异无显著性(P>0.05),而6、12、24h差异有显著性(P<0.05);缺血周边区脑组织NF-κBp65与ICAM-1的表达有明显的时间依从性。结论糖尿病大鼠缺血再灌注脑组织NF-κBp65和ICAM-1表达增加和表达时间提前可能是糖尿病加重脑缺血再灌注损伤的机制之一。     

白细胞介素8单克隆抗体对大鼠脑缺血再灌注损伤的保护作用

脑缺血再灌注损伤与炎症反应关系密切,白细胞介素8(IL8)作为一种中性粒细胞趋化因子,在脑缺血后炎症损伤中有重要作用[1]。我们设想IL8单克隆抗体(简称IL8单抗)可能对脑缺血再灌注损伤具有保护作用,在建立脑缺血再灌注模型基础上,侧脑室注射IL8单抗,通过观察脑梗死表1各组大鼠脑梗死灶体积及TUNEL、Bcl2及Bax阳性细胞数分组鼠数梗死灶体积(mm3)TUNELBcl2Bax生理盐水对照组6210.26±25.5845.82±7.0322.97±5.6470.16±8.54IL8单抗0.5μg组6207.25±28.5944.92±7.1124.46±6.3868.26±8.43IL8单抗1μg组6166.29±31.7338.87±7.1…     

β-七叶皂甙钠对大鼠局灶性脑缺血再灌注后NF-κB、ICAM-1、VCAM-1表达的影响

目的探讨大鼠局灶性脑缺血再灌注脑组织缺血区不同时间点NF-кB、ICAM-1、VCAM-1蛋白表达的变化,及β-七叶皂甙钠干预效果。方法采用大鼠大脑中动脉闭塞法(MCAO)制作局灶性脑缺血再灌注模型,用免疫组织化学方法观察大鼠脑缺血再灌注不同时间段,NF-кB、ICAM-1、VCAM-1蛋白的表达。并在大鼠于脑缺血前24h、1h及再灌注即刻分别腹腔给予β-七叶皂甙钠5mg/kg,2h MCAO,再灌注24h、48h后取脑,运用TTC染色测算脑梗死体积,免疫组化染色检测NF-кB、ICAM-1、VCAM-1蛋白表达,分析β-七叶皂甙钠的干预效应。结果(1)脑缺血后缺血区脑组织NF-кB及ICAM-1、VCAM-1表达均增加,NF-kB于再灌注后12～24h表达达高峰,Ⅰ- CAM-1于再灌注后24h表达达高峰,VCAM-1于再灌注后24～48h表达达高峰。(2)NF-кB的表达与血管内皮I- CAM-1、VCAM-1的表达呈正相关。(3)β-七叶皂甙钠能显著降低脑缺血再灌注后24h和48h缺血区NF-кB、ICAM- 1及VCAM-1的表达增加。(4)β-七叶皂甙钠能明显减轻脑缺血再灌注后的脑组织损伤,再灌注24h脑梗死体积减少41.8%。结论(1)脑缺血再灌注后NF-кB、ICAM-1、VCAM-1大量表达,这可能是脑缺血再灌注损伤机制之一。(2)脑缺血后NF-кB的活化可能与微血管内皮细胞ICAM-1、VCAM-1蛋白表达调控有关。(3)β-七叶皂甙钠能够减轻脑缺血后的脑组织损伤,有神经保护作用。     

Celecoxib对糖尿病大鼠缺血再灌注脑组织ICAM-1和MMP9表达及神经功能的影响

目的探讨celecoxib(塞来昔布)对糖尿病大鼠脑缺血再灌注后脑组织中ICAM-1和MMP9表达及神经功能的影响。方法将SD大鼠分为假手术组(S组)、脑缺血再灌注生理盐水组(NS组)、celecoxib低剂量组(LCIR组)和高剂量组(HCIR组)。采用腹腔注射链脲佐菌素(STZ)和线栓法制作糖尿病大鼠大脑中动脉缺血再灌注模型。分别于缺血后30min给予生理盐水或celecoxib溶液灌胃,再灌注后6、12、24、48h将大鼠断头取脑,免疫组化法检测脑组织中ICAM-1和MMP9的表达,并对大鼠进行神经功能缺损评分和死亡率的比较。结果 NS组、LCIR组、HCIR组大鼠神经功能缺损评分有显著差异(P<0.05);NS组、LCIR组、HCIR组MMP9及ICAM-1阳性血管主要表达于缺血周边区,较S组表达明显增强(P<0.05),LCIR组、HCIR组MMP9及ICAM-1阳性血管数较NS组减少(P<0.05),LCIR组、HCIR组之间差异不明显(P>0.05),各组不同时间点之间MMP9及ICAM-1阳性血管数均有明显差异(P<0.05)。经Celecoxib干预后大鼠死亡率明显下降。结论 celecoxib可能通过抑制脑组织中MMP9和ICAM-1的表达而减轻糖尿病大鼠脑缺血-再灌注后神经功能的损伤而降低实验大鼠的死亡。     

托吡酯对大鼠脑缺血再灌注损伤的神经保护作用

目的探讨托吡酯(TPM)对大鼠脑缺血再灌注损伤的神经保护作用及其机制。方法将健康30只雄性SD大鼠随机分为假手术组、缺血再灌注组和TPM干预组。用线栓法建立大鼠脑缺血再灌注模型,TPM干预组给予TPM80mg/kg腹腔注射,2次。缺血再灌注24h时进行神经功能评分、TTC染色法测量梗死体积、高效液相色谱分析法测定脑组织谷氨酸(Glu)及γ-氨基丁酸(GABA)的含量;免疫组化法检测GABAA受体阳性表达。结果(1)与缺血再灌注组比较,TPM干预组神经功能评分明显增高(P<0.01),脑梗死体积减少(P<0.05);(2)TPM干预组缺血侧脑皮质Glu含量显著低于缺血再灌注组(P<0.01),与假手术组比较差异无显著性;GABA含量显著高于假手术组和缺血再灌注组(均P<0.01);(3)TPM干预组缺血侧脑皮质GABAA受体阳性细胞数显著高于缺血再灌注组(P<0.01)。结论TPM对脑缺血再灌注损伤有神经保护作用,其机制可能为TPM降低兴奋性递质Glu水平、增加抑制性递质GABA的释放及GABAA受体的表达。     

脑缺血再灌注大鼠细胞间黏附分子-1、血管细胞间黏附分子-1的表达及β-七叶皂甙钠的干预作用

目的研究局灶性脑缺血再灌注过程中脑缺血区细胞间黏附分子-1(ICAM-1)、血管细胞间黏附分子-1(VCAM-1)的表达规律,并探讨β-七叶皂甙钠对其干预的脑保护作用。方法采用线栓法建立大鼠脑缺血再灌注模型,同时应用β-七叶皂甙钠予以干预。用HE染色和免疫组化染色观察大鼠脑缺血后再灌注不同时点组织学改变和ICAM-1、VCAM-1的阳性表达。结果(1)β-七叶皂甙钠明显减轻缺血再灌注后的脑组织损伤;(2)脑缺血再灌注后缺血区微血管内皮细胞ICAM-1、VCAM-1表达增加,ICAM-1于再灌注后24h表达达高峰,VCAM-1.于再灌注后24～48h表达达高峰,随后降低,但再灌注后72h两者表达仍高于正常水平;(3)β-七叶皂甙钠可以显著降低脑缺血再灌注后24h、48h缺血区ICAM-1、VCAM-1的表达。结论脑缺血再灌注后ICAM-1、VCAM—1大量表达,可能是脑缺血再灌注损伤的机制之一;β-七叶皂甙钠能降低ICAM-1和VCAM-1的表达及减轻脑组织损伤,有脑保护作用。     

Characteristics of the sympathetic innervation of the nictitating membrane and of the vasculature of the nose and tongue of the cat

Summary Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves.Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue, whose activity was revealed after-receptor blockade, had a similar threshold to the vasoconstrictor fibres.Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa.The preganglionic compound nerve action potential had four major components, S₁–S₄. S₁, S₂ and usually S₃ fibres were associated with membrane contraction; S₂, S₃ and sometimes S₁ fibres were associated with nasal vasoconstriction; and S₃, usually S₂ and occasionally S₁ fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S₄ fibres, may include fibres associated functionally with the three effectors.There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.     

Mechanisms of the suppression of the nociceptive reflex of the opening of the mouth during stimulation of the structures of the limbic brain

The comparative effectiveness of the inhibitory influence of tetanic stimulation of hypothalamus, amygdala and limbic cortex on EMG-response of m. digastricus evoked by electrical stimulation of tooth pulp nociceptive afferents was studied in cats anesthetized with a mixture of chloralose and nembutal. It was found that inhibition of the EMG-component of the jaw-opening reflex is most pronounced in case of stimulation of medial and lateral region of the hypothalamus, the inhibitory effect of central and medial nuclei of the amygdala is less pronounced and the effect of the limbic cortex is the weakest. It was shown that the mechanism of the antinociceptive effect of tetanic stimulation of the hypothalamus is not related to the concomitant increase of the blood pressure. After stabilization of the blood pressure the suppressive effect of the hypothalamus remains without changes, that points out to a direct, primary, not baro-afferent mechanism of the inhibition of the activity of nociceptive neurons of the trigeminal sensory nuclei. Noradrenaline, injected intravenously, induced a large increase of the blood pressure accompanied by a pronounced inhibition of the pain reflex. Angiotensin causes the same degree of blood pressure elevation without changes in the amplitude of the EMG-response of the pain reflex. Hypothalamic and noradrenergic mechanisms for control of pain sensitivity are discussed.     

Development of the projection from the nucleus of the brachium of the inferior colliculus to the superior colliculus in the ferret

Neurons in the deeper layers of the superior colliculus (SC) have spatially tuned receptive fields that are arranged to form a map of auditory space. The spatial tuning of these neurons emerges gradually in an experience-dependent manner after the onset of hearing, but the relative contributions of peripheral and central factors in this process of maturation are unknown. We have studied the postnatal development of the projection to the ferret SC from the nucleus of the brachium of the inferior colliculus (nBIC), its main source of auditory input, to determine whether the emergence of auditory map topography can be attributed to anatomical rewiring of this projection. The pattern of retrograde labeling produced by injections of fluorescent microspheres in the SC on postnatal day (P) 0 and just after the age of hearing onset (P29), showed that the nBIC-SC projection is topographically organized in the rostrocaudal axis, along which sound azimuth is represented, from birth. Injections of biotinylated dextran amine-fluorescein into the nBIC at different ages (P30, 60, and 90) labeled axons with numerous terminals and en passant boutons throughout the deeper layers of the SC. This labeling covered the entire mediolateral extent of the SC, but, in keeping with the pattern of retrograde labeling following microsphere injections in the SC, was more restricted rostrocaudally. No systematic changes were observed with age. The stability of the nBIC-SC projection over this period suggests that developmental changes in auditory spatial tuning involve other processes, rather than a gross refinement of the projection from the nBIC.     

Origins of the sympathetic innervation of the cervical end of the uterus in the rat

A retrograde neuronal tracer (Fast Blue) was injected in the cervical end of the uterine horn of virgin rats. The majority of the retrogradely labeled post-ganglionic sympathetic neurons were found in the sympathetic chain (74%). The superior mesenteric ganglia, inferior mesenteric ganglia and suprarenal ganglia accounted for 22, 3 and <1%, respectively. The distribution of neurons in the sympathetic chain labeled from the uterus resembles that described for other pelvic organs.     

Sexual pheromones and the evolution of the reward system of the brain: the chemosensory function of the amygdala

The amygdala of all tetrapod vertebrates receives direct projections from the main and accessory olfactory bulbs, and the strong similarities in the organization of these projections suggest that they have undergone a very conservative evolution. However, current ideas about the function of the amygdala do not pay sufficient attention to its chemosensory role, but only view it as the core of the emotional brain. In this study, we propose that both roles of the amygdala are intimately linked since the amygdala is actually involved in mediating emotional responses to chemical signals. The amygdala is the only structure in the brain receiving pheromonal information directly from the accessory olfactory bulbs and we have shown in mice that males emit sexual pheromones that are innately attractive for females. In fact, sexual pheromones can be used as unconditioned stimuli to induce a conditioned attraction to previously neutral odorants as well as a conditioned place preference. Therefore, sexual pheromones should be regarded as natural reinforcers. Behavioural and pharmacological studies (reviewed here) have shown that the females' innate preference for sexual pheromones is not affected by lesions of the dopaminergic cells of the ventral tegmental area, and that the systemic administration of dopamine antagonists do not alter neither the attraction nor the reinforcing effects of these pheromones. Anatomical studies have shown that the vomeronasal amygdala gives rise to important projections to the olfactory tubercle and the islands of Calleja, suggesting that these amygdalo-striatal pathways might be involved in the reinforcing value of sexual pheromones.     

Topographical organization of the motoneuron pools that innervate the muscles of the pinna of the cat

The topographical organization of the 22 motoneuron pools that innervate the pinna muscles of the cat was examined by injecting the B-subunit of cholera toxin conjugated to horseradish peroxidase into individual muscles. All 22 pools are found in the facial nucleus, organized as rostro-caudally oriented columns, and arranged according to the action of the muscles they innervate. Pools innervating muscles that pull the pinna dorsally are located in the dorsal two thirds of the medio-dorsal subdivision, and those innervating muscles that pull the pinna ventrally are located in the ventral one half of the nucleus. Motoneurons innervating muscles that pull the pinna cranially are located laterally, those that pull the pinna caudally are located medio-ventrally, and those that change the shape of the pinna are located along the entire dorso-ventral extent in the center of the medio-dorsal subdivision. This topographical layout is consistent with the somatotopic organization of the entire facial nucleus as demonstrated in a variety of species. © 1995 Wiley-Liss, Inc.     

Histochemical methods for the further characterisation of the tumourettes of the posterior lobe of the pituitary

Summary The granular cell tumourettes of the posterior lobe of the pituitary possess neuraminic acid containing carbohydrate. After removal of neuraminic acid with neuraminidase and exposure to FITC (Fluorescein isothiocyanate) labelled peanut agglutinin (Arachis hypogaea) (PNA), intracellular receptor structures could be demonstrated. The significance of the findings is discussed.