Ang-1、Ang-2差异表达在大鼠失血性休克血管反应性双相变化中的作用

目的:观察血管生成素-1(Ang-1)、血管生成素-2(Ang-2)在失血性休克后肠系膜上动脉中的表达变化,及其在失血性休克血管反应性双相变化中的作用。方法:采用离体微血管环张力测定技术和Western blotting技术,观察失血性休克后不同时点肠系膜上动脉(SMA)一级分支微血管环的血管反应性、SMA中Ang-1、Ang-2的蛋白表达变化;并观察在缺氧高血管反应期和低血管反应期,给予和抑制Ang-1、Ang-2对SMA一级分支血管环血管反应性的影响。结果:(1)失血性休克后,肠系膜上动脉血管反应性呈早期增高、晚期降低的双相变化,休克10min组NE的Emax最高,为正常的129.3%(P0.01);Ang-1的蛋白表达也呈早期增高、晚期降低的双相变化,休克10min组的Ang-1蛋白表达最高,为正常对照组的1.85倍;Ang-2的蛋白表达在休克早期变化不大,在休克后期逐渐增高,休克4h组的Ang-2蛋白表达最高,为正常对照组的2.90倍。(2)在高血管反应期(缺氧30min),外源性给予Ang-1对血管反应性影响不大,尽管NE的Emax增大,但无显著差异(P0.05),外源性给予Ang-2可降低血管反应性(P0.01);在低血管反应期(缺氧4h),外源性给予Ang-1可改善血管反应性(P0.01),外源性给予Ang-2可进一步降低血管反应性(P0.01)。结论:失血性休克后,肠系膜上动脉存在Ang-1、Ang-2的差异表达,这种差异表达参与了失血性休克血管反应性双相变化的形成。     

腺苷A3受体(A3AR)在失血性休克血管反应性调节中的作用

目的： 阻力血管对血管活性物质反应性的降低是决定创伤休克发生、发展及预后的重要因素。腺苷是机体遭受创伤、缺氧时大量释放的重要内源性调质,并通过相应受体发挥作用。本研究拟观察腺苷A3受体(A3AR)在失血性休克大鼠肠系膜上动脉的表达变化情况及其与休克血管反应性变化间的关系,初步探讨A3AR是否参与对休克血管反应性的调节。方法：参照以往的工作基础,建立大鼠失血性休克(40 mmHg)模型;大鼠肠系膜上动脉对缩血管物质去甲肾上腺素(NE)诱导的收缩反应性采用离体小血管张力测定仪检测;A3AR的蛋白及mRNA表达变化情况分别采用Western blotting及RT-PCR进行检测。结果：结果显示,在大鼠失血性休克后0-4 h,其肠系膜上动脉1-2级分支血管对由NE诱导的收缩反应性呈现“双向性”变化;A3AR mRNA表达随休克时间的延长呈逐渐降低的趋势,但无显著差异;而肠系膜上动脉血管平滑肌A3AR的蛋白表达在休克后即刻呈增加趋势,随着休克时间的延长,其表达逐渐下降,尤其以休克后4h的表达下降最为明显;此外,A3AR激动剂可部分恢复休克2 h大鼠肠系膜上动脉对NE的收缩反应性,且该作用可被A3AR阻断剂MRS1523所拮抗。结论：A3AR参与失血性休克血管低反应性的形成,在失血性休克后激动A3AR受体可保护血管功能,部分恢复失血性休克后大鼠阻力血管对NE的收缩反应性。     

血管平滑肌细胞钙库Ca~(2+)动员的变化在休克血管低反应性形成中的作用

目的:探讨大鼠腹主动脉血管平滑肌细胞(VSMCs)在缺氧培养时胞内钙库钙释放的变化情况,并探讨胞内钙库钙释放在休克血管对去甲肾上腺素(NE)低反应性中的可能作用,为进一步阐明休克血管低反应性的发生机制提供依据。方法:建立大鼠失血性休克(40mmHg,2h)的在体模型及大鼠VSMCs缺氧细胞模型;采用Fura-3/AM钙离子成像方法测定VSMCs胞浆钙离子浓度([Ca2+])的变化情况及其与IP3受体(IP3R)及雷诺定受体(RyR)介导的钙释放通道的关系;采用离体器官张力测定技术,检测不同内钙释放依赖信号通路在休克血管低反应性形成中的可能作用。结果:在细胞外液无Ca2+的前提下,NE可通过动员内钙释放引起VSMCs胞浆[Ca2+]的明显升高;缺氧培养后VSMCs胞浆[Ca2+]较正常对照组有所升高,由NE诱导的VSMCs胞浆[Ca2+]较对照组有所降低,但均无显著差别;但在缺氧培养的VSMCs,细胞内钙库钙释放功能明显改变,表现为与正常对照组比较,缺氧VSMCs由IP3R敏感钙释放通道开放剂adenophostinA(10-5mol/L)及ATP-Na2(10-4mol/L)诱导的VSMCs胞浆[Ca2+]升高不显著,但RyR敏感钙释放通道开放剂caffeine可诱导缺氧VSMCs胞浆[Ca2+]的明显升高;失血性休克(40mmHg,2h)可引起大鼠腹主动脉血管对由NE诱导的收缩反应性明显降低,IP3R激动剂ATP-Na2(10-4mol/L)并不明显提高休克血管对NE的收缩反应性,但IP3R阻断剂heparin(104U/L)可明显抑制休克血管对NE的收缩反应性;此外,在无钙及含钙的K-H液中,RyR阻断剂ryanodine(10-5mol/L)可部分恢复休克血管对NE的收缩反应性,而RyR激动剂caffeine(10-3mol/L)可进一步降低休克血管对NE诱导的收缩反应性。结论:失血性休克后由RyR介导的内钙释放被激活部分参与了休克血管低反应性的形成。     

缺血预处理对失血性休克大鼠血管反应性及钙敏感性的影响

目的：观察缺血预处理对失血性休克血管反应性和钙敏感性的影响。方法：通过观察不同缺血预处理方法对失血性休克大鼠存活时间和24 h存活率的影响,选择最适缺血预处理方法。在体实验,观察缺血预处理对失血性休克大鼠肠系膜上动脉（SMA）血管管径对去甲肾上腺素（NE）收缩反应性和NE升压反应的影响;离体实验,应用离体血管环张力测定技术,观察缺血预处理对失血性休克后大鼠SMA环血管反应性和钙敏感性的影响。结果：确定最适缺血预处理方法为：夹闭腹主动脉1 min,开放5 min,重复3次,2 h后复制失血性休克模型,这种方法可显著增加失血性休克大鼠的存活时间和24 h存活率。在体实验,缺血预处理可显著增加休克晚期NE的升压效应和在体SMA对NE的收缩反应（P<0.01）。离体实验,与失血性休克对照组比较,缺血预处理组SMA在休克早期(休克即刻)对NE的收缩反应性和钙敏感性明显下降（P<0.05）,但与正常对照组比较无显著差异（P>0.05）;在休克后期（休克2 h、3 h、4 h）,缺血预处理组SMA对NE的收缩反应性和钙敏感性显著增加（P<0.05）,且与正常对照组比较无显著差异（P>0.05）。结论：缺血预处理可能通过改善血管钙敏感性发挥对休克后期血管反应性的保护效应。     

失血性休克的大鼠肠系膜动脉节律基因表达的变化

目的:建立失血性休克大鼠模型及探讨失血性休克大鼠肠系膜上动脉(SMA)节律基因表达的变化。方法:建立失血性休克大鼠模型并随机分为失血性休克组和空白对照组,通过RT-PCR检测模型肠系膜上动脉节律基因per1、per2 mRNA的表达水平。结果:休克组与对照组相比,前者肠系膜上动脉节律基因per1、per2的mRNA表达降低(p<0.05)。结论:失血性休克模型肠系膜上动脉节律基因per1、per2表达水平下调,提示失血性休克可以影响节律基因的表达。     

吡那地尔预处理提高失血性休克血管的反应性和钙敏感性

目的:观察吡那地尔预处理诱导对失血性休克血管反应性和钙敏感性的保护作用以及与蛋白激酶C(PKC)α、ε的关系。方法:观察不同剂量吡那地尔在休克前不同时间预处理,对失血性休克大鼠去甲肾上腺素(NE)的升压效应[平均动脉压(MAP)增幅]和收缩血管效应[肠系膜上动脉(SMA)管径变化]的影响,以及对SMA一级分支微血管环血管反应性和钙敏感性的影响;观察PKCα、PKCε抑制剂对吡那地尔预处理诱导保护效应的影响,以及吡那地尔预处理对PKCα、PKCε蛋白转位的影响,证实PKCα和PKCε的作用。结果:(1)失血性休克2 h后,NE的升压效应和收缩血管效应、SMA血管反应性和钙敏感性较正常组均显著降低(P0.01),25μg/kgBW吡那地尔休克前30 min预处理可改善休克后的上述变化;(2)PKCα和PKCε的拮抗剂可以消除25μg/kg BW吡那地尔休克前30 min预处理诱导的失血性休克血管反应性和钙敏感性保护,使NE的Emax分别降低42.9%和62.9%(P0.01),使Ca2+的Emax分别降低31.1%和56.1%(P0.01);25μg/kg BW吡那地尔休克前30 min预处理使PKCα和PKCε的胞膜表达较休克2 h增高,胞浆表达较休克2 h降低(P0.01)。结论:吡那地尔预处理可通过诱导PKCα和PKCε的转位和活化,提高大鼠失血性休克后血管的反应性和钙敏感性。     

优降糖、TlRON对重症失血性休克大鼠的实验治疗

目的通过全身给予ATP敏感钾通道特异性阻滞剂优降糖和OONO-阻滞剂tiron治疗,探讨重症失血性休克新的治疗方法.方法将24只SD大鼠(体重200±1 0 g)制作脊斜肌的微循环观察标本,复制重症失血性休克模型,经股静脉注射实验药物,随机分为优降糖组,tiron组, 生理盐水对照组.分别观察药物对休克大鼠血管反应性、血压、微动脉血流量和24 h存活率的影响.结果休克2 h后,微血管NE的反应性显著降低,NE阈值由失血前的(0.16±0.05) mg/L上升到(4.27±1.62) mg/L.治疗2 h后NE阈值,优降糖组降为( 1.78±0.90) mg/L, 说明大鼠微血管反应性得到明显恢复;对照组仍为(4.14±0.90) mg/L.对多巴胺的升压效果 优降糖组是(25.25±3.25) mmHg明显高于对照组的(14.25±4.89) mmHg(P＜0.05).优降糖组大鼠在输回失去血液后血压稳定升高,治疗2 h后血压为(108.00±9.50) mmHg,24 h存活明显增多 (5/ 8),与对照组相比P＜0.01.而OONO-阻滞剂tiron只使微血管对NE反应性部分恢复, 在用药的5 min时NE阈值由(4.30±1.62) mg/L上升到(2.87±0.78) mg/L,24 h存活为(2 /8).对照组动物存活为(1/8).细动脉血流量与正常相比,对照组在治疗2 h后下降89% ,t iron组下降80%,优降糖组下降59%.讨论和结论1.大鼠失血性休克2 h 后,细动脉对N E反应阈值明显升高,说明重症休克时,细动脉血管反应性确实下降.我室前期研究表明重症休克时细动脉平滑肌细胞KATP开放导致细动脉平滑肌膜超极化,是血管反应性低下的重要原因. 本实验全身应用优降糖能较稳定地升高重症休克大鼠血压,增加细动脉流量,提高血管反应性,并能使休克动物24 h存活率提高50%,说明优降糖是一种治疗重症失血性休克的有效药物. 本实验结果显示,用OONO-阻滞剂tiron治疗重症失血性休克大鼠仅部分恢复A3动脉血管反应性,单纯用tiron尚不能明显提高失血性休克动物存活率.结论优降糖是一种能使微血管反应性恢复的药物,对重症失血性休克大鼠有较好的疗效,先以优降糖作为血管反应性恢复剂处理,再给升压药物(多巴胺)可明显提升动物血压,并提高动物存活率.     

阿片受体对失血性休克血管平滑肌细胞钙通道的调控作用

用全细胞(whol-cell)膜片箝记录技术研究失血性休克阻力血管对儿茶酚胺类血管活性药物的反应性降低时期,肠系膜动脉平滑肌细胞(VSMCs)Ca2 通道的变化,以及阻断阿片受体对它们的调控作用。结果发现:失血性休克阻力血管对NE的低反应期。血管平     

雌激素通过KATP通道影响大鼠肠系膜动脉的反应性

目的: 观察雌激素对大鼠肠系膜动脉平滑肌ATP敏感性钾离子通道 (K_ATP 通道)mRNA表达的影响,探讨K_ATP通道在雌激素调节大鼠肠系膜血管反应性中的作用。方法: 雌性SD大鼠48只,体重(100±10) g,随机分为假手术组(sham)、卵巢切除组(Ovx)和卵巢切除后补充雌激素组(Ovx +E)。采取实时荧光定量PCR检测大鼠肠系膜动脉中K_ATP通道mRNA的表达;观察各组大鼠肠系膜动脉对去甲肾上腺素(NE)升压效应的反应性。结果: 与sham组相比,Ovx组大鼠肠系膜动脉K_ATP 通道的Kir6.1及SUR2B亚单位mRNA表达减少(P<0.05),而Ovx+E组则表达增加(P<0.05)。与sham组相比,Ovx组大鼠的血管反应性明显增加(P<0.05),Ovx+E组无明显差异。给予K_ATP通道阻滞剂格列本脲后,sham组和Ovx+E组的动脉反应性增加(P<0.05),Ovx组无明显变化(P>0.05),此时3组间比较无明显差异(P>0.05)。结论: 雌激素可能通过上调肠系膜动脉平滑肌细胞K_ATP通道的表达来降低动脉对去甲肾上腺素升压效应的反应性。     

一氧化氮降低失血性休克血管反应性的机制

目的:探讨NO在失血性休克血管低反应性发生中的作用机制和防治。方法:复制SD大鼠失血性休克模型,测定脊斜肌微动脉对去甲肾上腺素(NE)的反应性。休克至血管反应性下降时,用同位素标记底物法测定脏器中NOS活性;分离肠系膜细动脉血管平滑肌细胞(ASMC),用荧光探针和共聚焦显微镜测定NO底物左旋精氨酸(L-Arg)和诱导性NOS(iNOS)抑制剂氨基胍(AG)对膜电位的影响;回输全部失血同时给L-Arg和AG观察其对大鼠24h存活率的影响。结果:休克至血管反应性降低时,心、肝NOS活性增加。L-Arg对对照组大鼠ASMC的膜电位无影响,但可使反应性低下大鼠的ASMC超极化;用AG预处理ASMC,则降低L-Arg引起的超极化幅度。回输全部失血时给AG可增加大鼠24h存活率。结论:HS后期ASMC中iNOS激活导致NO产生增加,并引起ASMC超极化可能是失血性休克后期血管低反应性发生的机制之一。     

Topical organization of the projections of neurons of the substantia nigra and the ventral field of the tegmentum of the midbrain to the head of the caudate nucleus of the cat

Neuroscience and Behavioral Physiology -     

Asymmetry of the internal connections of the striate cortex of the cat in the projection zone of the center of the field of vision

Studies were carried out on the organization of the internal connections of the striate cortex in cats in the projection zone of the center (0–5°) of the field of vision by microintophoretic application of horseradish peroxidase to electrophysiologically identified orientational columns. The area containing neurons showing retrograde labeling in most cases extended in the mediolateral direction. Labeled cells were located in the upper (II, III) and lower (V, VI) layers of the cortex, and the shapes and orientations of the areas containing labeled neurons in these layers coincided. Spatial asymmetry was detected in the distribution of labeled neurons relative to the orientational column studied. Labeled cells were located predominantly medial to the columns, regardless of the distance from the projection of the area centralis. Considering the visuotopical map of field 17, the asymmetry detected here provides evidence that neurons in orientational columns have more extensive connections with neurons of the peripheral part of the cortex. An asymmetrical distribution of “silent” zones around the receptive fields of neurons in orientational columns is suggested, and that these appear to receive influences from the periphery of the visual field. Laboratory of Visual Physiology and Laboratory of Central Nervous System Morphology, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, 199034 St. Petersburg, Russia. Translated from Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 82, No. 12, pp. 23–29, December, 1996.     

Characteristics of the topographic interrelation of the head of the pancreas and the duodenum and pathology of the organs of the pancreatoduodenal area

Seventy pancreatoduodenal complexes of 55 patients with chronic pancreatitis and tumours of this zone and 15 patients died from other diseases are studies histotopographically . The pieces of the pancreatic head tissue in the medial wall of the duodenum were found in 12 cases of the first group and in 4 control cases. The pancreatic tissue consisted either of all elements of this organ or cystically dilated ducts and seemed to infiltrate different layers of the duodenum wall. Three variants of the pancreatic head structure are suggested on the basis of anatomo-topographical interrelationships of the pancreatic head and duodenum. In 12 out of 14 cases chronic pancreatitis and carcinoma of organs of this zone were combined with the variants of the pancreatic head structure, in 2 cases there was a true heterotopy . Pathogenetic significance of these variants for the development of chronic pancreatitis is discussed.     

Influence of the level of the transmembrane potential on the dynamics of the extinction of the amplitude of the synaptic reactions of the snail under voltage clamping conditions

The influence of the level of the transmembrane potential on the dynamics of the extinction of the amplitudes of summary excitatory postsynaptic currents arising in identified giant parietal neurons in response to rhythmic stimulation of the intestinal nerve was investigated in a preparation of the isolated CNS of the common snail in order to identify the possibility of the participation of the postsynaptic element in synaptic plasticity. It was demonstrated that, at a greater value of the transmembrane potential, the decrease in the amplitudes of the postsynaptic currents which have been induced by rhythmic stimulation takes place more rapidly. It was also demonstrated that at a higher frequency of stimulation of the nerve, the effect of the influence of the membrane potential level on the dynamics of the synaptic reactions is more prominent. The data obtained may be regarded as an argument in favor of the possibility of the participation of the post-synapse in plasticity. This study was partially supported by the Russian Basic Research Fund (project No. 94-04-12209). Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow. Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 45, No. 1, pp. 171–179, January–February, 1995.     

Effects of the lesion of the postcommissural part of the septum on the behavior of the rat.

The effects of the lesion of the postcommissural part of the septum on behavior of the rat has been studied. Results may be summarized as follows. An increase in the exploratory behavior in the open field which decreases rapidly; a decrease in the number of defecations in this test and a decrease in time leaving a dark environment for exploration. In the shuttle box test, no facilitation of the acquisition, but a permanent and quite significant increase in the intertrial activity has been found. We conclude that the lesions tend to decrease the emotivity of the subjects. An interpretation on the basis of the species -- specific defensive reactions explains the transitory and permanent effects of the lesions on the spontaneous activity.     

Effect of the conditions of adaptation of the optic analyzer to the function of the thermoreceptors of the human skin

Summary A discussion is presented of the effect produced by light stimulation applied to the optic analyzer alone on the function of the temperature analyzer. The cutaneous-temperature analyzer was kept on constant illumination and temperature. The light effects from the retinal photoreceptors on the cutaneous thermoceptor system led to reflex changes of the functional rate of the latter. Conditions of the optic analyzer of light adaptation caused reflex adjustment of cold receptors as to heating. Dark adaptation of the eyes changed the functional state of the cold receptors, corresponding to their adjustment to low temperatures.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 57, No. 3, pp. 3–6, March, 1964