不同光波长对三疣梭子蟹大眼幼体至Ⅱ期仔蟹期间存活和生长的影响

在水温26±2℃下,将三疣梭子蟹大眼幼体饲养于500 m L塑料杯中,置于不同波长LED光照下,研究不同波长光照对三疣梭子蟹大眼幼体至Ⅱ期仔蟹期间存活和生长的影响。结果显示:各波长光照下大眼幼体至Ⅰ期仔蟹(M→C1)期间存活率没有显著差异(P0.05),而Ⅰ期仔蟹蜕壳至Ⅱ期仔蟹期间(C1→C2)在光波长为500～510 nm和600～605 nm下的存活率显著高于其它组(P0.05);在450～455 nm光波长下M→C1以及C1→C2的蜕皮(壳)周期最短,增重率和特定生长率最高,综合各项指标来看,波长为450～455 nm波长的光照对三疣梭子蟹大眼幼体及Ⅰ期仔蟹的存活及生长是最有利的。     

5-HT在青年和老年猫腰髓中分布的比较研究

用免疫组织化学方法观察了5-HT(5-羟色胺)在青年猫与老年猫腰髓中的表达,比较其表达的差异性,探讨该差异的原因及可能的生理影响.在青年猫与老年猫L6段脊髓灰质中,5-HT能神经元与神经纤维分布广泛,多个Rexed板层均可见5-HT阳性神经元,主要分布于RexedⅠ、Ⅱ、Ⅶ、Ⅸ区.5-HT能神经纤维阳性较强的区域有RexedⅠ、Ⅱ区及RexedⅦ、Ⅷ区.RexedⅩ区未见阳性标记.经比较,老年组腰髓中5-HT能神经元的数量及免疫反应性均明显低于青年组.表明猫腰髓中的5-HT表达有明显的年龄相关变化,该变化与脊髓中5-HT的合成、重摄取及代谢分解功能的变化有关,可能对脊髓水平伤害性信息的调制有重要影响.     

中枢5-HT与运动性中枢疲劳

阐述了运动性疲劳的含义、主要表现、发生的机理,及神经递质的确定条件和主要类型以及研究意义,总结了运动对5-HT代谢及浓度变化的影响以及此种影响对疲劳的作用的研究现状:1.长时间运动促进了脂肪酸的动员和支链氨基酸供能,从而提高了血浆中游离色氨酸的浓度。2.5-HT不能通过血脑屏障,而游离色氨酸可以通过血脑屏障。3.色氨酸是5-HT的合成前体。4.5-HT是一种抑制性神经递质。5.不管是长时间耐力运动还是急性剧烈运动都能引起大脑中5-HT浓度的升高。6.疲劳时5-HT浓度最高。7.5-HT引起中枢疲劳的神经通路和可能的机理。8.药物介导显示5-HT浓度升高,疲劳加剧。9.补充支链氨基酸对延长运动时间有意义。10.运动训练可以提高机体对5-HT浓度变化的适应。     

大鼠游泳训练对脑组织5-HT分解代谢的影响

为观察游泳训练对大鼠下丘脑、纹状体5-羟色胺（5-HT）及其分解代谢物5-羟吲哚乙酸（5-HIAA）的影响,本研究采用荧光光度法测定了不同游泳训练和水环境及安静时大鼠下丘脑和纹状体5-HT和5-HIAA水平.结果表明,与安静组相比,除游泳训练组和一次水环境组大鼠下丘脑中5-HT有升高趋势外,其余各组升高显著;除一次水环境组较安静组大鼠纹状体中5-HT有升高趋势外,其余各组5-HT都显著升高;一次游泳组和游泳训练24h恢复组大鼠下丘脑5-HIAA较安静组有下降趋势,其余各组有升高趋势;除长期水环境组大鼠纹状体5-HIAA较安静组有升高趋势外,其余各组都显著升高.提示,经过游泳训练可使脑内的5-HT和5-HIAA有所提高,说明训练有助于脑机能的改善和加快运动后的恢复,并可一定程度提高脑组织神经活动的稳定性和对运动的适应性,5-HT可能是运动性中枢疲劳较为敏感的神经介质.     

脑组织中5-HT及受体与运动的研究现状

运用文献资料法,系统地概括了脑内5-羟色胺（5-hydroxytryptamine,5-HT）及其受体的特性,并总结了近年来脑内5-HT及受体与运动的研究现状：1．5-HT作为一种抑制性神经递质可以降低从中枢向外周发放的冲动,导致中枢疲劳。2．5-HT的升高可能首先发生在某一脑区而非全脑。3．耐力运动中大脑5-HT含量升高且在疲劳时加剧。4．力竭运动可同时加快5-HT的合成和降解速度,脑内5-HT在运动即刻几乎没有明显变化。5．5-HT受体各亚型存在较大差异,有的起抑制性作用,有的则发挥兴奋性作用。     

家兔消化道5-HT免疫反应阳性肥大细胞

利用免疫组化技术和组织化学(甲苯胺蓝和中性红)技术,对家兔消化道5-HT免疫反应阳性细胞、肥大细胞(MC)进行了研究,并通过邻片法比较探讨了2种细胞的对应关系.家兔食管部呈免疫组化阴性反应,其余部位均有免疫反应阳性细胞;在胃和肠中5-HT阳性细胞多分布在粘膜上皮和固有层,MC主要分布在粘膜和粘膜下层结缔组织中.有18%～48%的MC与免疫组化染色的邻片中5-HT阳性细胞在位置上相对应,它们为5-HT阳性MC,有7%～20%的5-HT免疫反应阳性细胞为MC.结果表明家兔消化道中有分泌5-HT的MC,MC是消化道5-HT的来源之一.     

中华绒螯蟹仔蟹必需脂肪酸营养需求研究

通过正交试验法设计含亚油酸,亚麻酸,二十碳五烯酸和二十二碳六烯酸四种必需脂肪酸三因素三水平的饲料进行试验。结果表明,中华绒螯蟹从大眼幼体到仔Ⅲ期间的成活率,体重增长率和体宽增长率均受必需脂肪酸含量及其比例的影响。在本试验中,中华绒螯蟹仔蟹对亚油酸,亚麻酸,二十碳五烯酸和二十二碳六烯酸的最适需求量（%）分别为2.79、0.95,0.28和0.53。亚油酸与亚麻酸及亚油酸与二十二碳六烯酸的最佳比例分别为2.93和5.26。就中华绒螯蟹仔蟹而言,二十碳五烯酸和二十二碳六烯酸的营养生理作用最大,其次是亚麻酸,最后为亚油酸,试验结果还表明,中华绒螯蟹由大眼幼体发育至Ⅲ期仔蟹共历经三次蜕皮,首次蜕皮不受试验饵料中必需脂肪酸含量的影响。但第二次和第三次蜕皮却却受饵料中EPA和DHA含量的显著影响。此外,试验中Ⅲ期仔蟹的体脂组成随饲料不同而发生变化。并与其所摄食饲料的脂肪酸组成相类似。     

福沙匹坦联合5-HT3受体拮抗剂预防化疗相关性呕吐的临床观察

观察福沙匹坦联合5-HT3受体拮抗剂方案预防化疗相关性呕吐的疗效和不良反应.采用的方法:选择60例经病理确诊的恶性肿瘤接受化疗的患者,随机分为2组,观察组30例,采用福沙匹坦、5-HT3受体拮抗剂(托烷司琼或格拉司琼)及地塞米松三联方案,对照组30例,采用5-HT3受体拮抗剂(托烷司琼或格拉司琼)、地塞米松二联方案.观察两种方案对两组患者抗肿瘤化疗后急性期(0-24h)及延迟期(24-120h)呕吐的预防情况并记录两组患者不良反应发生情况.取得以下结果:在入组的60例患者中,福沙匹坦联合5-HT3受体拮抗剂(托烷司琼或格拉司琼)、地塞米松三联方案组和5-HT3受体拮抗剂(托烷司琼或格拉司琼)、地塞米松二联方案组对急性期呕吐的完全缓解率分别为76.7％和56.7％,有效控制率分别为90％和80％.对延迟期呕吐的完全缓解率分别为70％和43.3％,有效控制率分别为86.7％和70％.两组止吐药物相关不良反应无明显差异.可以认为,福沙匹坦联合5-HT3受体拮抗剂(托烷司琼或格拉司琼)、地塞米松三联方案对化疗引起的急性及延迟性呕吐疗效确切,为提高化疗患者生活质量提供了较好的选择方案,治疗的依从性好,值得推广.     

巨细胞网状核5-HT能纤维对小脑浦肯野细胞自发电活动的影响

用电生理学方法、观察了小脑皮层第Ⅵ—Ⅶ小叶蚓部的浦肯野细胞（Purkinje cell,PC）对巨细胞网状核（Gigantocellularis reticularis nucleus,GI）刺激的反应特性,并观察了颈静脉注射5-羟色胺（5-HT）受体阻断剂二甲麦新碱（Methysergide）后GI刺激的效应。 结果表明:（1）刺激GI对小脑皮层Ⅵ—Ⅶ小叶PC自发放电的影响有抑制（41％）、兴奋（27％）及无明显作用（32％）三种形式,其中以抑制性作用为主。（2）GI刺激引起的PC反应在小脑皮层上呈区域性差异,表现为由VIA（64.3％）、VTB（65.3％）、VIC（71.4％）至Ⅶ小叶（74.2％）PC反应比率逐渐升高。（3）颈静脉注射二甲麦角新碱后,由GI刺激引起的PC自发放电的抑制性效应可逐渐被消除,而兴奋性效应则不被减弱。 结果提示:GI—小脑之间存在着5-HT能纤维投射,这些5-HT能纤维可能以“非突触释放”的形式调节着PC的机能活动。PC对GI刺激反应的区域性差异,可能与GI—小脑5-HT能纤维投射的解剖学分布特性有关。     

孕鼠子宫内5-HT免疫反应阳性肥大细胞的研究

以正常孕鼠和自然抗着床鼠的子宫为实验材料,采用组织化学和免疫组织化学技术,研究了小鼠子宫肥大细胞(mast cell,MC)在胚泡着床前后(孕3~7 d)表达5-羟色胺(5-hydroxytryptamine,5-HT)的状况.结果表明:(1)绝大多数子宫MC为5-HT免疫反应阳性,阳性率在77.3%~93.6%之间;(2)自然抗着床鼠的5-HT阳性率显著高于正常孕鼠(P<0.05).实验结果提示:(1)子宫MC是孕鼠子宫内5-HT的重要来源,5-HT在着床过程中可能具有免疫调节作用;(2)子宫内MC表达5-HT量的异常与抗着床现象的发生有一定的关系.     

5-HT3 receptors are membrane ion channels

The neurohormone 5-hydroxytryptamine (5HT or serotonin) exerts its effects by binding to several distinct receptors. One of these is the M-receptor of Gaddum and Picarelli, now called the 5-HT3 receptor, through which 5-HT acts to excite enteric neurons. Ligand-binding and functional studies have shown that the 5-HT3 receptor is widely distributed in peripheral and central nervous tissue and evidence suggests that the receptor might incorporate an ion channel permeable to cations. We now report the first recordings of currents through single ion channels activated by 5-HT3 receptors, in excised (outside-out) membrane patches from neurons of the guinea pig submucous plexus. Whereas application of acetylcholine activated predominantly a 40-pS channel, 5-HT caused unitary currents apparently through two channels of conductances of 15 and 9 pS, which were reversibly blocked by antagonists of the 5-HT3 receptor. Receptors for amine neurotransmitters, including 5-HT1 and 5-HT2, have previously been thought to transduce their effects through GTP-binding proteins: the direct demonstration that 5-HT3 receptors are ligand-gated ion channels implies a role for 5-HT, and perhaps other amines, as a 'fast' synaptic transmitter.     

5-HT 6受体拮抗剂三维定量构效关系研究

为指导合成高效的5-HT6受体拮抗剂,采用比较分子场分析(CoMFA)和比较相似性指数分析(CoMSIA)对143个5-HT6受体拮抗剂数据进行了三维定量构效关系(3D-QSAR)研究,分别得到了具有良好可靠性和预测能力的CoMFA(Q2=0.513,R2ncv=0.864,R2pre=0.731)和CoMSIA模型(Q2=0.515,R2ncv=0.844,R2pre=0.777).由模型的等势线图分析,可得如下结论:大体积及/或电负性较大的R2取代基、疏水性R3和疏水性苯环R1位取代基、可作氢键受体的R2取代基、可作氢键供体的R3取代基有助于增大活性.这些结论能够更好地帮助理解5-HT6受体拮抗剂的抑制机理,并为今后的药物设计与合成提供新思路.     

小鼠胃肠道5-羟色胺免疫反应阳性肥大细胞

利用免疫组化技术和甲苯胺蓝(TB)染色技术,对小鼠胃肠道5-羟色胺免疫反应阳性细胞(5-HT+细胞)、肥大细胞(MC)和5-羟色胺免疫反应阳性肥大细胞(5-HT+MC)进行了研究.结果表明:小鼠胃肠中5-HT+细胞多分布于黏膜上皮细胞之间、腺泡上皮细胞之间和固有层内;MC多分布于黏膜层和黏膜下层结缔组织之中;小鼠胃和小肠中分别有49%和47%的MC与免疫组化染色的邻片中5-HT+细胞在位置上相对应,该部分MC为5-HT+MC;小鼠胃和小肠中分别有24%和20%的5-HT+细胞为MC.本文从形态学的角度证明了小鼠胃肠道MC可分泌5-HT,MC是消化道5-HT的来源之一.     

Orphanin FQ antagonizes the analgesic effect of 5-HT in rat brain

Orphanin FQ (OFQ) is a new modulatory peptide which was found in 1994. It mediates in morphine analgesia and electroacupuncture analgesia. The interaction between OFQ and 5-hydroxytryptamine (5-HT) on analgesia was observed using the method of intracere-broventricular microinjection. The results showed that cumulative i. c. v. administration of gradually increasing doses of 5-HT produced a dose-dependent analgesia, and administration of different doses of OFQ separateness had no significant effect on tail flick latency, but 1 or 10 μg OFQ could reverse the analgesia induced by 5-HT, suggesting that OFQ could antagonize the analgesia induced by 5-HT in rat brain.     

A cytoplasmic region determines single-channel conductance in 5-HT3 receptors

5-hydroxytryptamine type 3 (5-HT3) receptors are cation-selective transmitter-gated ion channels of the Cys-loop superfamily. The single-channel conductance of human recombinant 5-HT3 receptors assembled as homomers of 5-HT3A subunits, or heteromers of 5-HT3A and 5-HT3B subunits, are markedly different, being 0.4 pS (refs 6, 9) and 16 pS (ref. 7), respectively. Paradoxically, the channel-lining M2 domain of the 5-HT3A subunit would be predicted to promote cation conduction, whereas that of the 5-HT3B subunit would not. Here we describe a determinant of single-channel conductance that can explain these observations. By constructing chimaeric 5-HT3A and 5-HT3B subunits we identified a region (the 'HA-stretch') within the large cytoplasmic loop of the receptor that markedly influences channel conductance. Replacement of three arginine residues unique to the HA-stretch of the 5-HT3A subunit by their 5-HT3B subunit counterparts increased single-channel conductance 28-fold. Significantly, ultrastructural studies of the Torpedo nicotinic acetylcholine receptor indicate that the key residues might frame narrow openings that contribute to the permeation pathway. Our findings solve the conundrum of the anomalously low conductance of homomeric 5-HT3A receptors and indicate an important function for the HA-stretch in Cys-loop transmitter-gated ion channels.     

5-HT3 receptors mediate inhibition of acetylcholine release in cortical tissue

The release of cerebral acetylcholine from terminals in the cerebral cortex has been shown to be regulated by 5-hydroxytryptamine (5-HT) but it is not known which subtype of the 5-HT receptor is involved. 5-HT receptor agonists increase acetylcholine levels in vivo, indicating a reduced turnover, and reduce release of acetylcholine from striatal slices in vitro. Depleting 5-HT by inhibiting synthesis or by destroying the neurons containing 5-HT potentiates acetylcholine release, and increases acetylcholine turnover in the cerebral cortex and hippocampus. Selective antagonists for the 5-HT3 receptor subtypes which seem to have effects on mood and activity may exert their effect through the regulation of acetylcholine release in the cortex and limbic system. Radioligand binding studies show a high density of 5-HT3 receptors in the cholinergic-rich entorhinal cortex and we provide evidence that a reduction in cortical cholinergic function can be effected in vitro by 5-HT3 receptors.     

陈旧性腰椎间盘突出症治疗前后对血清5-HT及5-HIAA的影响

目的：推拿“六法”及硬膜外给药治疗,对陈旧性腰椎间盘突出症患者血清5－HT及5HIAA含量的影响。方法：运用荧光分光光度法测试血清5－HT及5－HIAA含量。结果：治疗后患者血清中5－HT及5－HIAA浓度明显回降。结论：说明上述中西医结合法治疗可以减少5－HT的合成代谢,同时增强了它们的分解代谢。