侧脑室注射Orexins对大鼠摄食的影响及机制

目的:探讨侧脑室注射orexins(食欲素)、NPY(神经肽Y)、MCH(黑色素聚集激素)和甘丙肽对大鼠摄食的影响及其机制。方法:将成年雄性Wistar大鼠随机分为对照组、侧脑室注射组和室旁核(PVN)注射组。通过套管将orexin-A、orexin-B、NPY、MCH和甘丙肽分别注射至侧脑室和PVN内,随后测量大鼠食物摄入量,并检测PVN、弓状核(ARC)和VMH内c-fos的表达。结果:与对照组比较,侧脑室注射NPY、MCH和orexin-B 2 h后,大鼠摄食量显著增多(P0.05)。相较于orexin-B和MCH,NPY对摄食的影响更显著(P0.05)。与NS对照组比较,侧脑室注射甘丙肽和orexin-A 1 h后,大鼠摄食量显著增多(P0.05)。与NS对照组比较,侧脑室注射orexin-A可显著增加c-fos在PVN和ARC中的表达,在VMH中效应较弱(P0.05)。与NS对照组比较,PVN注射NPY能显著增加大鼠2 h摄食量(P0.05),PVN注射orexin-A能显著增加大鼠2 h和4 h摄食量(P0.05)。结论:orexins与可促进大鼠摄食,此效应可能通过下丘脑参与摄食调控中枢PVN和ARC而实现的。     

下丘脑Nesfatin-1抑食效应及机制研究

目的:探讨下丘脑nesfatin-1与组胺信号通路间的相互作用及对摄食的影响。方法:采用第三脑室置管、药物注射、免疫组化、ELISA等方法,观察氟甲基组氨酸(FMH)、α螺旋促肾上腺皮质激素释放激素(CRH)和促甲状腺激素释放激素(TRH)对Nesfatin-1诱导的抑制摄食的影响,以及Nesfatin-1与组胺信号通路相互影响调控摄食机制。结果:第三脑室注射nesfatin-1可显著减少大鼠摄食量,而第三脑室内预先注射FMH,nesfatin-1抑制摄食效应明显减弱,但FMH本身并不影响大鼠夜间摄食量。第三脑室注射nesfatin-1,可显著增加优降宁诱发的PVN、腹内侧核(VMH)、结节乳头核(TMN)内t-MH的积累;但腹腔注射nesfatin-1没有引起大鼠摄食改变,t-MH蓄积也无显著变化。第三脑室注射α螺旋CRH或抗TRH血清均可显著减弱nesfatin-1的抑食效应,而α螺旋CRH、抗TRH血清本身并不显著影响大鼠摄食量。第三脑室注射nesfatin-1可显著增加下丘脑PVN内CRH和TRH水平,且nesfatin-1可显著增加优降宁诱导的PVN、VMH和TMN内t-MH的表达,而α螺旋CRH或抗TRH血清可显著抑制nesfatin-1诱导的PVN、VMH和TMH内t-MH的蓄积。第三脑室注射组胺可显著增加大鼠下丘脑PVN内nesfatin-1含量,但LH、VMH、TMN以及血浆内nesfatin-1水平无显著改变。免疫组化研究显示,PVN内有nesfatin-1和H1-R免疫反应阳性神经元,且部分神经元共存。结论:Nesfatin-1的抑食效应可能与下丘脑组胺信号通路介导。     

大鼠室旁核注射orexin-A对体重的影响

目的:探讨大鼠室旁核(PVN)注射orexin-A对体重的影响。方法:大鼠室旁核(PVN)微量注射orexin-A,用大脑置管埋管、组织化学染色等方法探讨PVN注射orexin-A对其体重的影响。结果:与安慰剂组大鼠相比,PVN注射orexin-A组大鼠体重明显减轻(P0.05),而orexin-A组和安慰剂组摄食量无明显差异(P0.05)。注射结束后6天,orexin-A处理大鼠的体重仍显著低于注射前(P0.05),而安慰剂组大鼠则比注射前显著增重(P0.05)。药物注射可显著降低机体脂肪,但并不特异存在于注射orexin-A或安慰剂的大鼠身上。Orexin-A组和安慰剂组大鼠的肌肉量和脂肪量均显著降低(P0.05),但注射orexin-A的大鼠降低更明显。与安慰剂组相比,orexin-A处理后的摄食转化率显著降低(P0.05)。结论:大鼠室旁核(PVN)注射orexin-A可通过增加活动量产生负能量平衡,引起体重减轻。     

下丘脑LHA-VMH Ghrelin信号通路对肥胖大鼠摄食选择、胃肠道运动及自发活动的影响及机制研究

目的:探究下丘脑外侧区(LHA)-腹内侧核(VMH)ghrelin信号通路对肥胖大鼠的摄食选择、胃肠道运动及自发活动的影响。方法:采用免疫组织化学方法检测大鼠LHA中ghrelin受体的表达;观察LHA注射ghrelin对大鼠摄食选择胃肠道运动及自发活动的影响;电损毁VMH,观察LHA注射ghrelin对大鼠摄食的影响。结果:免疫组化结果显示,大鼠下丘脑LHA中存在ghrelin受体,且LHA-VMH之间存在纤维投射;大鼠LHA微量注射ghrelin后,肥胖(DIO)大鼠及肥胖抵抗(DR)大鼠的正常饮食、高脂饮食及高糖饮食均高于正常大鼠,但预注射ghrelin受体拮抗剂[D-Lys3]-GHRP-6 (DLS)能够阻断这种作用;而电损毁大鼠VMH,显著减弱了ghrelin对正常大鼠、DIO大鼠及DR大鼠的促摄食作用。大鼠LHA微量注射ghrelin后,正常大鼠、DIO大鼠及DR大鼠的自发活动中,X轴、Y轴方向上的活动增加,且总活动增加,但Z轴方向上活动无明显改变;此外,LHA注射ghrelin,DIO大鼠及DR大鼠的胃肠道转运速率明显加快,且DR大鼠胃肠道转运速率增加更为明显,而预注射ghrelin受体拮抗剂[D-Lys3]-GHRP-6(DLS)显著阻断ghrelin的促胃肠道转运作用。结论:下丘脑LHA-VMH ghrelin信号通路参与调节正常大鼠、DIO及DR大鼠的摄食选择、胃肠道运动及自发活动。     

下丘脑外侧区注入胃泌素对大鼠胃酸分泌的影响

本工作观察了下丘脑外侧区(LHA)、腹内侧核(VMH)或侧脑室(LCV)注射17肽胃泌素(G17)或五肽胃泌素(G5)对清醒大鼠胃酸分泌的影响。结果表明,将 G17或 G5注入 LHA可引起胃酸分泌明显增加,而将 G5注入 VMH、LCV 或静脉则不影响胃酸分泌;切断迷走神经可以阻断在 LHA 注入 G5引起胃酸分泌增加的效应;在阿托品背景下,将 G5注入 LHA仍能引起胃酸分泌明显增加;静脉注射酚妥拉明,心得安或纳洛酮均不影响 G5对 LHA 刺激胃酸分泌的作用。这些结果提示:LHA 是胃泌素作用的一个特异性部位,由 LHA 发出的冲动可能通过迷走神经内的两种传出纤维引起胃酸分泌,一为胆碱能纤维,另一为非胆碱能非肾上腺素能纤维。     

胃动素受体激动剂红霉素对大鼠下丘脑葡萄糖反应神经元的作用

目的:通过观察胃动素受体激动剂红霉素对大鼠下丘脑中葡萄糖反应神经元电活动的影响,探讨中枢胃动素对摄食活动调控的机制.方法:应用细胞外记录神经元单位放电的方法,记录麻醉大鼠LHA及VMH的神经元电活动.左颈总动脉注射0.56 mol/L葡萄糖溶液0.2 ml鉴别GSNs及GRNs;侧脑室注射红霉素4 μg,观察其对葡萄糖反应神经元及非葡萄糖反应神经元自发放电频率的影响;侧脑室注射GM-109(胃动素受体拮抗剂)与红霉素的混合剂(1:50的比例配制),观察上述效应是否可重复出现.结果:在LHA,红霉素对GSNs有明显的兴奋作用,与其对该核团NGSNs的作用相比较,差别有统计学意义(P＜0.05);在VMH,红霉素对GRNs有明显的抑制作用,与其对该核团NGRNs的作用相比较,差别有统计学意义(P＜0.01).对红霉素有反应的神经元在给予GM-109和红霉素的混合剂后,神经元的放电频率无明显变化.结论:胃动素受体激动剂红霉素可兴奋LHA-GSNs同时抑制VMH-GRNs,这一途径可能是中枢胃动素促进摄食活动的神经调节机制之一.     

下丘脑腹内侧核损毁对大鼠nesfatin-1/NUCB2表达的影响

目的:观察下丘脑腹内侧核(VMH)损毁对大鼠脂肪组织nesfatin-1/NUCB2表达的影响及其机制。方法:电损毁VMH,观察大鼠体重和脂肪组织变化,采用Western blot检测脂肪组织中nesfatin-1/NUCB2表达改变。腹腔注射6-羟多巴胺(50 mg/kg)以阻断交感神经;持续外周注射卡巴胆碱(180μg/kg)用以模拟VMH损毁,观察其对大鼠皮下脂肪nesfatin-1/NUCB2表达的影响。结果:与对照组和假手术组比较,VMH损毁后大鼠体重明显增加(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)也显著增多;Western blot分析结果显示,nesfatin-1/NUCB2在胰腺和肝脏中表达较多,但皮下、肠系膜脂肪和肩胛间棕色脂肪组织(i BAT)中表达较少,骨骼肌(腓肠肌)中鲜有表达;与对照组和假手术组比较,VMH损毁组大鼠nesfatin-1/NUCB2在肝脏、胰腺、骨骼肌和i BAT中表达无显著差异(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)nesfatin-1/NUCB2表达显著增多与对照组相比,6-羟多巴胺组nesfatin-1/NUCB2表达显著升高(t=3.43,P0.05),而卡巴胆碱组nesfatin-1/NUCB2表达无显著差异(t=0.37,P=0.72)。结论:VMH损毁后大鼠脂肪组织nesfatin-1/NUCB2表达改变可能通过抑制交感神经活动介导。     

基于PI3K/PKB通路研究EGCG对CVB3感染致病毒性心肌炎小鼠细胞凋亡的影响

细胞凋亡是造成病毒性心肌炎(VMC)发病过程中心肌损伤的重要因素;表没食子儿茶素没食子酸酯(EGCG)对缺血再灌注引起的细胞凋亡具有抑制作用,但是否抑制VMC发病过程中的心肌细胞凋亡尚不明确.因此,本研究将分析EGCG对VMC小鼠细胞凋亡的影响及分子机制.BALB/c小鼠随机分为对照组、VMC组(腹腔注射CVB3悬液造模)、VMC+EGCG组(腹腔注射CVB3悬液造模后腹腔注射EGCG)、VMC+EGCG+LY组(腹腔注射CVB3悬液造模后腹腔注射EGCG及P13K抑制剂LY294002).检测血清心肌损伤标志物肌钙蛋白I(cTnI)及乳酸脱氢酶(LDH),心肌中CVB3滴度及RNA表达、HE染色、凋亡基因及p-PI3K、p-PKB表达.结果显示,与对照组比较,VMC组血清cTnI、LDH含量、心肌中CVB3滴度及RNA表达、细胞凋亡率、cleaved caspase-3表达升高,心肌中Survivin、p-PI3K、p-PKB表达降低(P＜0.05);与VMC组比较,VMC+EGCG组血清cTnI、LDH含量及心肌中细胞凋亡率、cleaved caspase-3表达降低,心肌中Survivin、p-PI3K、p-PKB表达升高(P＜0.05),心肌中CVB3滴度及RNA表达无明显变化(P＞0.05);与VMC+EGCG组比较,VMC+EGCG+LY组血清cTnI、LDH含量、心肌中细胞凋亡率、cleaved caspase-3表达升高,心肌中Survivin、p-PI3K、p-PKB表达降低(P＜0.05),心肌中CVB3滴度及RNA表达无明显变化(P＞0.05).以上结果表明EGCG对VMC小鼠心肌细胞凋亡具有抑制作用且该作用与激活PI3K/PKB通路有关.     

大鼠下丘脑LHA-PVN nesfatin-1神经通路构成及对胃运动的影响

目的:阐述LHA和PVN间nesfatin-1神经通路的构成,探讨PVN nesfatin-1对胃收缩幅度及频率的影响及潜在机制。方法:采用荧光金逆行追踪结合荧光免疫组化技术,观察LHA-PVN间nesfatin-1神经通路构成;采用细胞外放电记录,观察nesfatin-1对GD放点活动的影响;通过在体胃运动技术,观察nesfatin-1对清醒自由活动大鼠胃收缩幅度和频率的影响。结果:Nesfatin-1能够抑制GD-E神经元放电(1.97±0.12 Hz vs.1.15±0.07 Hz)促进GD-I神经元放电(1.74±0.10 Hz vs.3.04±0.18 Hz),H4928能够部分阻断nesfatin-1对GD神经元(GD-E:1.38±0.08 Hz,P0.05 vs.nesfatin-1;GD-I:2.49±0.15 Hz,P0.05 vs.nesfatin-1)的影响;PVN内微量注射nesfatin-1能够抑制大鼠胃运动,呈量效依赖关系;LHA和PVN间有nesfatin-1神经纤维联系;电刺激LHA后,GD神经元放电频率增加(GD-E:2.06±0.12 Hz vs.4.23±0.21 Hz,GD-I:1.61±0.09 Hz vs.4.83±0.25 Hz),预先向PVN注射抗NUCB2/nesfatin-1抗体后,GD-E神经元放电频率减弱(4.91±0.25 Hz vs.4.23±0.21 Hz),而GD-I神经元放电频率增强(4.15±0.18 Hz vs.4.83±0.25)。结论:PVN内nesfatin-1可调控大鼠GD神经元放电活动及胃运动,该效应受LHA调控。     

室旁核注射胰高血糖素样肽-1对不同病程糖尿病大鼠胃排空的影响

目的:研究下丘脑室旁核(paraventricular nucleus,PVN)注射胰高血糖素样肽-1(GLP-1)对糖尿病早期大鼠胃排空的影响,并探讨其相关作用机制.方法:60只清洁级雄性Wistar大鼠随机分为正常对照组(NC组),糖尿病组(DM组),GLP-1干预组(GLP-1组),每组各20只,后两组腹腔注射链脲佐菌素(STZ)制备糖尿病模型,分别于注射STZ2周、6周后每组随机取半数进行实验,实验前于无菌条件下大鼠一侧下丘脑PVN区埋置套管,GLP-1组经套管注入GLP-1,NC组及DM组注入等体积生理盐水.酚红灌胃法检测胃排空率,酶联免疫吸附法(ELISA)测定血浆GLP-1浓度,半定量RT-PCR法测定胃窦、胃底GLP-1RmRNA表达.结果:注射STZ2周后,DM组较NC组胃排空率显著升高(P＜0.01).GLP-1组胃排空率低于DM组(P＜0.01),血浆GLP-1浓度高于DM组及NC组(P均＜0.05),胃窦GLP-1RmRNA表达明显高于DM组、NC组(P均＜0.01).注射STZ 6周后,DM组胃排空率高于NC组(P＜0.01).GLP-1组较DM组胃排空率显著降低(P＜0.01),血浆GLP-1浓度、胃窦GLP-1RmRNA表达显著高于DM组、NC组(P均＜0.01).结论:下丘脑PVN区注射GLP-1后,可减慢糖尿病大鼠初期加速的胃排空,原因可能与血浆GLP-1浓度及胃窦GLP-1RmRNA表达增加有关.     

Reliability of Analyses of Hg,Fe, Ca,K, P,pH, Alkalinity,Conductivity, Hardness and Colour from Lakes

The aim of this report has been to present results concerning analytical quality controls of Hg analysis of fish and sediment, analyses of Fe, Ca, total-P, K, pH, alkalinity, conductivity, colour and hardness (Ca + Mg) of lake water samples. Despite the fact that these are standard parameters in many regular water control programs, there are major differences in the reliability with which these parameters can be determined. The focus here is on an overall inter-laboratory comparison between the parameters. Six laboratories have been involved in the analysis. Selected results: pH gives the lowest (average) relative standard deviation (error), about 2 %; conductivity gives an error of about 5–7 %; alkalinity yields an average error of as much as 13–25 %, which is the largest among the parameters studied here; colour also gives a high error, 9–15 %; hardness gives a relative standard deviation of about 6–7 %. Of the other parameters (i. e., Hg, Fe, Ca and P), Hg gives the best reliability and Fe and P the lowest. To have knowledge of the reliability of the analytical data is of paramount importance in most control programs and research projects.     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.     

Uniform hypothesis of cell behavior--movement, contact inhibition of movement, adhesion, chemotaxis, phagocytosis, pinocytosis, division, contact inhibition of division, fusion.

The cell has been represented as a charged liquid drop. Contrary to the DLVO-theory, the effect of the surface potential upon the value of the interfacial tension of the cell membrane has also been taken into consideration. The cell membrane has visco-elastic properties and its constituents may move against each other. Cell movement is caused by the appearance of a small number of the electrically charged constituents of the cell membrane on the leading edge of the cell. This produces a local decrease in the surface tension and the cell membrane expansion. At the moment of contact between two cells proton transfers occur between the strongly negatively charged microvilli of one cell and the body of the other, analogous to a condenser breakdown. This, through the effect on the surface tension, causes contact inhibition of movement. The distribution of the proton dissociable groups modifies the interaction between the cells (differentiation) and between the cell and the substratum (adhesion). Adsorption of the charged compounds at the surface of the cell membrane, decreasing the surface potential and increasing the surface tension, causes the phenomena of chemotaxis, phagocytosis and pinocytosis. Cell division, considered in the terms of the surface energy, requires an adequate supply of considerable quantities of energy inversely proportional to the surface potential value. In case of a reduction of the distance between the cells, their surface potential and the energetic barrier of the cell division processes increases, and causes contact inhibition of cell division. Due to their high charge, division of neoplastic cells is inhibited much later than division of normal cells, or is completely ininhibited due to geometric conditions. Fusion of the cell membrane in the intra-cellular and intercellular processes is a reverse process in relation to the cell division.     

The effect of malathion,diazinon, and various concentrations of zinc,copper, nickel,lead, iron,and mercury on fish

Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive to diazinon. Long-term exposure to pesticides modified morphology and behavior. The LC50-96 values for Cu, Hg, and Pb were 0.3, 0.16, and 0.44, respectively, for smaller fish and 1.0, 0.77, and 1.33, respectively, for larger fish. Replicate LC50 values for Zn, Ni, and Fe were somewhat variable, and for these metals, the size of the fish seemed to affect response because LC50 values increased as fish size increased. Cooper, Pb, Zn, and Fe residues following exposure to sublethal concentrations of these metals for 15 d were significantly greater in whole juvenile common carp than in controls.     

The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.     

Further studies of the sieve-element plastids of theCaryophyllales includingBarbeuia,Corrigiola, Lyallia,Microtea, Sarcobatus,andTelephium

The sieve-element plastids of 69 species of theCaryophyllales were investigated by transmission electron microscopy. All contained the specific subtype-P3 plastids characterized by a peripheral ring of protein filaments. The presence or absence of an additional central protein crystal and their shape being either polygonal or globular as well as the average sizes of the sieve-element plastids are useful features in the characterization of some families.—Barbeuia contains sieve-element plastids that confirm its placement within thePhytolaccaceae. Lyallia differs fromHectorella by including small starch grains in their sieve-element plastids, which otherwise by their globular crystals negate a closer connection to theCaryophyllaceae. The lack of a central protein crystal in its form-P3fs plastids placesMicrotea best within theChenopodiaceae. Sarcobatus, a so far uncontested member of theChenopodiaceae, contains form-P3cf plastids, i.e., including a central crystal not found elsewhere in this family.Telephium andCorrigiola, shifted back and forth betweenMolluginaceae andCaryophyllaceae, have form-P3cf(s) plastids with a polygonal crystal which favor their placement within theCaryophyllaceae.     

Definitions,measurements, and classifications of stimuli,situations, and environments

A review is presented of issues relevant to the definition, measurement, and classification of stimuli, situations, and environments. Problems such as the lack of adequate definitions of concepts, error and bias in measurement procedures, confusion between measurement of a concept and measurement of its behavioral effects, and the lack of agreement among alternative measures are emphasized. It is suggested that concepts be defined in terms of objective characteristics while allowing for the study of the transactional relationship between organism and environment. The work of the ethologists in defining stimuli while studying their relationship to different organismic states and situational contexts is emphasized in this regard. Following Brunswik, it is also suggested that wherever possible there be a representative sampling of variables in natural settings. Note from the editors: From time to time, Human Ecology will publish a review article. Our first in this series is a review by a psychologist of basic definitional and conceptual problems in environmental studies.This paper was prepared while the author was a Visiting Research Fellow at the Educational Testing Service. The support of ETS and my colleagues in the Division of Psychological Studies is gratefully acknowledged. The review was also supported in part by a grant from the Rutgers University Research Council.     

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS

The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.