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1.
α-MSH对EGTA发热的作用   总被引:3,自引:3,他引:0  
目的:观察α-MSH对EGTA发热反应的作用及其可能机制。方法:建立EGTA发热模型;在离体条件下,应用Fura-2荧光指示剂测定细胞内Ca2+浓度([Ca2+]i);体外培养下丘脑神经细胞。结果:α-MSH能明显抑制EGTA性发热反应(P<0.01);EGTA可以降低下丘脑神经细胞[Ca2+]i水平(P<0.01),但α-MSH不影响正常下丘脑神经细胞[Ca2+]i及EGTA对下丘脑神经细胞[Ca2+]i的作用(P>0.05);EGTA可刺激体外培养的下丘脑神经细胞释放CRH(P<0.05),而α-MSH能抑制EGTA的这种作用(P<0.05)。结论:α-MSH抑制中枢发热介质CRH的产生可能是降低EGTA发热反应的主要机制之一;中枢CRH的产生和释放增加可能是EGTA性发热的一个重要因素。  相似文献   

2.
缺氧对培养的猪肺内皮细胞胞浆游离钙的影响   总被引:1,自引:0,他引:1  
本文应用荧光探针Fura-1/AM测定胞浆游离钙浓度([Ca^2+]i)技术,观察培养的猪肺动脉内皮细胞[Ca^2+]i在缺氧时变化。实验发现:向细胞悬液中充氮气造成缺氧时,肺动脉内皮细胞[Ca^2+]i升高81±21%(P<0.05,n=8)。结果提示肺动脉内皮细胞钙信使系统可能参与缺氧所致血管反应。  相似文献   

3.
本文应用pH敏感的BCECF和Ca敏感的Furaα萤光染料,分别测定雄性。16周龄SHRSP和WKY循环淋巴细胞pHi,Na ̄+-H ̄+交换活性和[Ca ̄(2+)]i,结果表明SHRSP循环淋巴细胞pHi、Na ̄+-H ̄+交换活性和[Ca ̄(2+)]i均显著高于WKR,而细胞缓冲能力在两组大鼠之间没有显著差异。提示在SHRSP细胞膜可能存在Na ̄+,H ̄+交换遗传性缺陷。将两组大鼠的资料合并,经直线回归相关分析发现pHi与Na ̄+-H ̄+交换活性和pHi与[Ca(2+)]i均呈显著正相关。表明Na ̄+-H ̄+交换活性和[Ca ̄(2+)]i参与pHi调节.它们之间既相互调节又相互制约。细胞内Na、Ca和细胞膜Na ̄+-H ̄+离子转运系统异常可能是高血压病因中重要因素之一。  相似文献   

4.
钙离子与牛磺酸两者跨心肌细胞膜内流的相互影响   总被引:1,自引:2,他引:1  
目的和方法:取新生SD大鼠心室肌制备培养搏动心肌细胞,采用放射性同位素45Ca2+及3H-牛磺酸示踪技术,观察钙离子与牛磺酸跨心肌细胞膜内流的相互影响。结果:(1)牛磺酸内流在低胞外Ca2+浓度([Ca2+]o,0.5mmol/L)和高[Ca2+]o(40mmol/L)均比正常[Ca2+]o(15mmol/L)和高[Ca2+]o(40mmol/L)时增加,尤以低[Ca2+]。时明显;异搏定(10μmol/L)能促进牛磺酸的内流;(2)10~20mmol/L牛磺酸对不同[Ca2+]。(05、15和40mmol/L)下的Ca2+内流均有抑制作用,而1mmol/L牛磺酸只抑制高[Ca2+]o时Ca2+内流,对低[Ca2+]o和正常[Ca2+]o时Ca2+内流无明显作用;1~20mmol/Lβ-丙氨酸对Ca2+内流无明显影响。结论:胞外Ca2+浓度的变化可直接影响牛磺酸内流,而牛磺酸能抑制Ca2+的内流,两者相互影响,从而发挥牛碘酸调节细胞内Ca2+浓度的作用  相似文献   

5.
下丘脑[Ca^2+]i,cAMP在家兔EGTA性发热机制中的作用   总被引:10,自引:3,他引:10  
用60只新西兰兔分两部分进行实验。(1)用12只制备下丘脑细胞悬液,在离体条件下,应用Fura-2荧光指示剂测定细胞内Ca^2+浓度(Ca^2+]i)。结果表明,用EGTA络合神经细胞外Ca^2+而降低细胞外Ca^2+浓度时,下丘脑神经细胞([Ca^2+]i)明显降低(P>0.01);相反,增加细胞外Ca^2+浓度,则[Ca^2+]i明显增高(P>0.01)。(2)用48只家兔分4组,分别向侧脑室  相似文献   

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本文比较了卒中型自发往高血压鼠(SHRsp)和京都Wistar正常血压鼠(WKY)心肌线粒体Ca ̄(2+),Mg ̄(2+)-ATPase活力及膜流动性。用定磷法测得WKY和SHRsp的Ca ̄(2+),Mg ̄(2+)-ATPase活力(25℃)分别为0.287±0.016及0.218±0.017μmol/(min.mg)(-x±Sx)。SHRsp心肌线粒体Ca ̄(2+),Mg ̄(2+)-ATPase活力降低24.7%,两组比较有显著差异(P<0.01,n=9).以DPH标记心肌线粒体膜,测得WKY和SHRsp的荧光偏振值分别为0.187±0.003及0.181±0.003(P>0.05,n=6)。  相似文献   

7.
本文应用细胞膜放射标记和离子交换层析法测定巨噬细胞(MФ)内肌醇-1,4,5-三磷酸(IP3)、用Ca ̄(2+)指示剂的分光光谱法测定MФ内Ca ̄(2+)浓度([Ca ̄(2+)])、用APAAP桥联酶标法检测MФ表面Ia抗原的表达,研究去甲肾上腺素(NE)对大鼠腹腔的MФ内IP3、[Ca ̄(2+)]i和MФ表面la抗原表达的影响。结果显示NE(10 ̄(-8)mol/L)可显著增高MФ中IP_3含量(442±22cpm/10 ̄6cells,对照组102±8cpm/10 ̄6cells,P<0.01);NE可使MФ内[Ca ̄(2+)]i显著增高(322±78nmol/L,对照组97±17nmol/L,P<0.01);NE可显著增高MФ表面I-A、I-E抗原的表达(64±8%、58±6%,对照组50±3%,44±4%,P<0.01)。提示神经递质NE促进MФ表面Ia抗原表达的作用可能是通过第二信使IP_3和Ca ̄(2+)介导的。  相似文献   

8.
目的:观察ISO心肌坏死时大鼠心肌细胞核钙转运系统的改变。方法:大鼠心肌坏死模型采用皮下注射ISO制备,心肌细胞核采用差速离心和密度梯度离心分离纯化,用酶学方法鉴定核的纯度及测定ATPase活性,用45Ca2+同位素法测定核钙摄取。结果:与对照组相比,ISO坏死心脏组织呈显著的损伤和坏死,心系数增加35%(P<0.01),心肌组织MDA和钙含量分别增加57%和80%(P<0.01)。与对照组相比,ISO心肌坏死细胞核Ca-ATPase的[Ca2+]反应Vmax降低27.5%(P<0.01),Ka无显著变化;对[ATP]反应的Vmax无显著变化,而Km增加61.7%(P<0.05);ISO组45Ca2+摄取显著降低(P<0.01),Vmax与对照组相比降低46.1%(P<0.01),Km无显著变化。结论:坏死心肌细胞核钙转运系统功能显著降低,可能与心肌坏死时细胞核功能紊乱有关  相似文献   

9.
目的:观察异丙嗪(promethazine,PMZ)对家兔EGTA性发热的影响并探讨其作用机制。方法:侧脑室和静脉给药。用Fura-2荧光分光光度法测定细胞内游离钙浓度([Ca2+]i)。结果:(1)侧脑室灌注06μmolEGTA引起家兔明显的发热反应,侧脑室灌注06μmolEGTA20min后,静脉注射PMZ(5mg/kg)明显抑制EGTA引起的结肠温度上升,其3h发热反应指数明显低于侧脑室灌注06μmolEGTA20min后静脉注射生理盐水(NS)组。而侧脑室灌注人工脑脊液(ACSF)20min后静脉注射PMZ(5mg/kg)组家兔结肠温度明显低于ACSF+NS对照组。(2)体外实验发现,向下丘脑细胞悬液中加入终浓度为074mmol/L的PMZ,下丘脑细胞[Ca2+]i从(1592±188)nmol/L升高到(5337±901)nmol/L(P<005)。结论:PMZ诱导体温调节中枢神经细胞[Ca2+]i升高可能是PMZ抑制家兔EGTA性发热的中枢机制之一。  相似文献   

10.
用Fura-2荧光测定法和RIA,对24例慢性肾功能衰竭(CRF)维持血透患者(男16例,女8例,年龄26~71岁,平均50.9岁)血小板的胞浆游离钙浓度和血栓素B2(TXB2)含量进行了测定。CRF组透析前、后血小板胞浆游离钙浓度均高于正常对照组(P均<0.001),透析后低于透析前(P<0.002);透前、后血小板TXB2均低于正常(P分别小于0.001和0.05),透析后高于透析前(P<0.001)。血小板胞浆钙浓度变化与TXB2生成不相关。P<0.001:与透析前比,ΔP<0.05,ΔΔP<0.002在相关分析上,Pt[Ca2+]i与血小板TXB2在正常对照组不相关(r=-0.27,p<0.1),透析前、后也均不相关(r=0.34和-0.22,p分别<0.2和0.5)。讨论Ca2+是重要的细胞内信使,多种形式的细胞损伤或细胞处于病理生理状态下,常伴有胞浆钙水平的增高。血小板胞浆Ca2+在刺激信号的转导中发挥重要的作用,促使血小板的变形、聚集、释放,调节血小板的花生四烯酸代谢[3]。有关研究已证实,血小板[Ca2+]i的变化能诱发内源性花生四烯酸代谢物的释放,参与TXA2生成的调节;而TXA2对[Ca  相似文献   

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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.  相似文献   

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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.  相似文献   

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The hip joints of 30 human male and female fetuses and stillborns between 20 mm and 350 mm crown-rump length were studied by light microscopy. The ligament of the head of the femur developed in situ as a condensation of mesenchyme at the end of the second month of intra-uterine life (IUL), and was vascularized by branches of acetabular vessels early in the fourth month. In the majority of fetuses older than 5.5 months IUL, vessels in the ligament passed a short way into the femoral head within cartilage canals, to supply a small region around the fovea capitis. The remainder of the head was supplied by vessels in canals from around the upper part of the neck. The ligament changed from predominantly cellular to fibrous during the last 4 months of IUL. This increase in strength suggested significant mechanical functions in utero: limitation of adduction-flexion and opposition to postero-superior dislocation were the most likely.  相似文献   

14.
This paper reviews the lifetime contributions of the author to the field of sleep-wakefulness (S-W), reinterprets results of the early studies, and suggests new conclusions and perspectives. Long-term cats with mesencephalic transection show behavioral/polygraphic rapid eye movement sleep (REMS), including the typical oculo-pupillary behavior, even when the section is performed in kittens prior to S-W maturation. REMS can be induced as a reflex. Typical non-rapid eye movement S (NREMS) is absent and full W/arousal is present only after a precollicular section. The isolated forebrain (IF) rostral to the transection exhibits all features of W/arousal and NREMS [with electroencephalographic (EEG) spindles and delta waves], arousal to olfactory stimuli, and including the appropriate oculo-pupillary behaviors. These features also mature normally after neonatal transection. REMS is absent from the IF. After deprivation there is NREMS pressure and rebound in the IF, but the decerebrate cat only shows pressure for REMS. Most IF reactions to pharmacologic agents are within expectations, except for the tolerance/withdrawal effects of long-term morphine use which are absent. In contrast, these effects are supported by the brainstem (i.e. seen in the decerebrate cat). In cats with ablation of the telencephalon, or diencephalic cats, delta waves are absent in the thalamus. EEG thalamic spindle waves are seen triggering S for only 4-5 days after ablation. Therefore, true NREMS is absent in chronic diencephalic cats although pre- and postsomniac behaviors persist. These animals are hyperactive and show a pronounced, permanent insomnia; however, a low dose of barbiturate triggers a dramatic REMS/atypical NREMS rebound. Cats without the thalamus (athalamic cats), initially show a dissociation between behavioral hyperactivity/insomnia and the neocortical EEG, which for 15-20 days exhibits only delta and slower oscillations. Fast, low-voltage W rhythms appear later on, first during REMS, but spindle waves and S postures are absent from the start, such that these cats also display only atypical NREMS. Athalamic cats also show barbiturate-sensitive insomnia. Cats with ablation of the frontal cortices or the caudate nuclei remain permanently hyperactive. They also show a mild, but significant hyposomnia, which is permanent in afrontal cats, but lasts for about a month in acaudates. The polygraphic/behavioral features of their S-W states remain normal. We conclude and propose that: (a) the control of the S-W system is highly complex and distributed, but is organized hierarchically in a well-defined rostro-caudal manner; the rostral-most or highest level (telencephalon), is the most functionally complex/adaptative and regulates the lower levels; the diencephalic/basal forebrain, or middle level, has a pivotal role in inducing switching between S and W and in coordinating the lowest (brainstem) and highest levels; (b) W can occur independently in both the forebrain and brainstem, but true NREMS- and REMS-generating mechanisms exist exclusively in the forebrain and brainstem, respectively; (c) forebrain and brainstem S-W processes can operate independently from each other and are preprogrammed at birth; this helps understanding normal and abnormal polygraphic/behavioral dissociations in humans and normal dissociations/splitting in aquatic mammals; (d) NREMS homeostasis is present in the IF, but only REMS pressure after deprivation persists in the decerebrate cat; (e) the thalamus engages in both NREMS and W; (f) insomnia in diencephalic cats is the result of an imbalance between antagonistic W- and S-promoting cellular groups in the ventral brain (normally modulated by the telencephalon); (g) the EEG waves, which are signature for each S-W state, appear to truly drive the concomitant behaviors, e.g. a hypothetical human IF could alternate between behavioral NREMS and W/arousal/awareness; (h) a role for REMS is to keep the individual sleeping at the end of the self-limiting NREMS periods. The need for accelerating research on telencephaling NREMS periods. The need for accelerating research on telencephalic S-W processes and downstream control of the lower S-W system levels is emphasized.  相似文献   

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Studies reported here show that intrastriatal administration of corticoliberin to rats decreases the blood testosterone level. However, in conditions of chemical deficiency of dopaminergic transmission in the dorsal striatum induced by injection of 6-hydroxydopamine, the effect of this neurohormone did not appear. It is concluded that extrahypothalamic corticoliberin is involved in regulating the hormonal reproductive system acting via dopaminergic mechanisms. Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 85, No. 4, pp. 594–597, April, 1999.  相似文献   

18.
The endothelium of the ocular drainage system (Schlemm’s canal, collector tubules, and aqueous veins) in primary juvenile glaucoma undergoes degenerative dystrophic changes with compensatory hypertrophy and proliferation at the initial stages of the glaucomatous process and atrophy and desquamation at advanced and terminal stages. Progressive decrease in the pinocytous function of endotheliocytes, reduction of the protein-synthesizing and mitochondrial compartments of the cytoplasm, and formation of autophagosomes reflect the process of endotheliocyte degeneration in general. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 5, pp. 574–577, May, 2008  相似文献   

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