霞水母糖蛋白抗疲劳作用的实验研究

本文对霞水母糖蛋白的抗疲劳作用进行了研究。试验中分别以50、100、200mg／kg剂量的霞水母糖蛋白经口给予小鼠连续灌胃30d,然后分别进行小鼠负重游泳试验、血清尿素氮、肝糖原及血乳酸测定。结果显示,霞水母糖蛋白各剂量组小鼠的游泳时间明显长于对照组（P〈0．01）;各剂量组小鼠运动后血清尿素氮含量低于对照组（P〈0．05或P〈0．01）;中、高剂量组小鼠肝糖原含量均明显高于对照组（P〈0．01）;各剂量组小鼠运动后的血乳酸含量均小于对照组（P〈0．01）。从而表明,霞水母糖蛋白具有抗疲劳作用。     

高原红景天抗疲劳作用的研究

目的：探讨高原红景天在抗运动性疲劳的作用,并阐明其抗疲劳的作用机制。方法：将200只雄性ICR小鼠随机分为四组（n=50）,即：负重游泳组、血清尿素氮测定组、血乳酸测定组和肝糖原测定组;每个大组又随机将小鼠分成5个小组（n=10）：低、中、高剂量红景天组、空白（H,O）对照组和糖（13．3％葡萄糖溶液）对照组。比较各组小鼠体重、力竭性游泳时间、血清尿素、血乳酸浓度及肝糖原水平的变化。结果：红景天各剂量组与空白对照组、糖对照组相比,负重游泳时间均明显延长（P〈0．05）;高、中、低各红景天剂量组均可使运动后小鼠的血尿素含量显著降低（P〈0．05）;中、高红景天剂量组与2个对照组相比,均明显提高了小鼠肝脏内肝糖原的含量;10min游泳后,各组小鼠体内的血乳酸值都有了相应程度的提升,各剂量红景天组血乳酸值与2个对照组差异均具有显著性（P〈0．05）。20rain休息后各测量组小鼠体内的血乳酸值都有不同程度的下降。结论：红景天具有延缓疲劳发生和促进疲劳恢复的作用。     

阿里红多糖对小鼠抗疲劳和耐缺氧的作用*

目的:研究阿里红多糖对小鼠的抗疲劳和耐缺氧作用。方法:将48只小鼠随机分为4组(n=12),即对照组,低、中、高剂量阿里红多糖组(100、200、400 mg/kg)。各组小鼠按0.20 ml/10 g每日连续灌胃21 d后,观察不同剂量的阿里红多糖对小鼠负重游泳时间,运动后血清尿素氮、血乳酸、肝糖原、肌糖原含量和常压耐缺氧存活时间、断头后呼吸维持时间的影响。结果:与对照组相比,阿里红多糖能延长小鼠负重游泳时间、耐缺氧存活时间及断头后呼吸维持时间,其中中、高剂量组差异均极显著(P＜0.01),低剂量组差异显著(P＜0.05);阿里红多糖能降低运动小鼠血清尿素氮、血乳酸含量,增加运动小鼠肝糖原、肌糖原含量,且大都差异显著(P＜0.05)或极显著(P＜ 0.01)。结论:阿里红多糖具有抗疲劳作用和提高耐缺氧能力作用。     

蚂蚁水提取物抗疲劳的研究

目的:研究蚂蚁水提取物抗疲劳作用及其机制,为提高运动员训练效果及比赛成绩提供科学方法。方法:将80只小鼠随机分为4组(n=20):阴性生理盐水对照组、蚂蚁水提取物分为高、中、低三个剂量组,比较各组小鼠力竭游泳时间、肝糖原、肌糖原、乳酸脱氢酶、超氧化物歧化酶、血乳酸和血尿素氮的差异,研究蚂蚁水提取物抗疲劳的效果和机制。结果:与阴性生理盐水对照组比较,蚂蚁水提取物中高剂量组能够延长小鼠负重游泳时间(P<0.01),提高小鼠乳酸脱氢酶、超氧化物歧化酶活力(P<0.01),降低血乳酸和血尿素氮含量(P<0.01),提高小鼠肌糖原储备量,但对肝糖原的储备量影响不大。结论:蚂蚁水提取物能起到抗疲劳作用,其原因可能是它提高了乳酸脱氢酶、超氧化物歧化酶活力,使得代谢产物的分解加快,从而小鼠在耐力运动中坚持更久的时间。     

双歧杆菌发酵果蔬汁对小鼠抗疲劳作用的实验研究

目的检测发酵果蔬汁对小鼠的抗疲劳作用。方法将3种果蔬汁按一定比例加入双歧杆菌、保加利亚乳杆菌和嗜热链球菌,经发酵,分别以高中低3个剂量喂食小鼠30d后,进行小鼠负重游泳实验,检测肝糖原、乳酸和尿素氮等各项抗疲劳指标。结果3种果蔬汁均能显著延长小鼠负重游泳时间,提高小鼠肝糖原的储备量;降低小鼠游泳后血乳酸和尿素氮均值,增加血红蛋白含量及乳酸脱氢酶活性,减少血尿酸含量。且抗疲劳强度程度与型量声低有一定相差。结论3种发酵果蔬汁具有抗疲劳作用。     

玄参多糖成分抗疲劳活性的研究

研究了玄参（Scrophularia ningpoensis Hemsl．）多糖类成分对小鼠抗疲劳的药理作用。取雄性（♂）昆明种小鼠,体重22—27g,随机分为空白对照组、香菇多糖阳性对照组、玄参多糖（低、中、高）剂量3组,经灌胃分别给予小鼠生理盐水、香菇多糖及玄参多糖类成分100、200、400mg·kg^-1·d^-1,连续灌胃21d。分别观察小鼠的体重变化情况,负重游泳力竭时间,血清尿素氮、肝糖原和血乳酸的含量。结果表明,玄参多糖类成分可降低运动后小鼠血清尿素氮、血乳酸含量,增加小鼠肝糖原含量,具有抗疲劳的活性作用。     

花生肽对小鼠的抗疲劳作用研究

目的：探讨花生肽对ICR小鼠的抗疲劳作用。方法：采用SPF级雄性ICR小鼠80只按体重随机分为4组,分别为空白对照组、3个花生肽干预组（250、500、1 000 mg/kg BW］。每日经口灌胃给予受试样品水溶液,干预周期为30 d,干预结束后进行负重游泳试验,并对各组小鼠负重游泳力竭时间进行记录,同时对其血糖水平、血清尿素氮含量及乳酸脱氢酶活力进行测定,并检测各组小鼠血乳酸水平,检测各组小鼠肝、肌糖原含量,并测定小鼠血清生化指标,同时测定小鼠心肌、肝脏及腓肠肌氧化应激和脂质过氧化指标水平。结果：与空白对照组相比,花生肽可显著延长小鼠负重游泳力竭时间,并提高其乳酸脱氢酶活性,降低运动后小鼠血乳酸含量,加强肌糖原储备,提高心肌SOD活力。结论：花生肽具备一定的抗疲劳作用。     

富硒板党抗疲劳和抗缺氧作用的实验研究

目的：探讨富硒板党抗疲劳、抗缺氧作用及其机制。方法：昆明种小鼠随机分为对照组和富硒板党低、中、高剂量组,小鼠连续灌胃30d,分别测定小鼠负重游泳、抗缺氧时间;测定血红蛋白（Hb）、血乳酸（LAC）、血清尿素氮（BUN）和肝糖原含量;测定乳酸脱氢酶（LI）H）及超氧化物歧化酶（SOD）fi~活性。结果：与对照组比较,富硒板党低、中、高剂量组可延长小鼠负重游泳、抗缺氧时间（P〈O．05,P〈O．01）,明显增加陆和肝糖原舍量（P〈O．05）,明显增加LDH及SOD的活性（P〈0．05,P〈0．01）,降低LAC及BUN的含量（P〈O．05）,与低剂量组比较,中、高剂量组作用效果较好（P〈O．05）。结论：富硒板党具有明显抗疲劳、抗缺氧作用。     

海豹油抗疲劳作用研究

目的考察海豹油的抗疲劳效果。方法将小鼠随机分为4大组,各大组分为玉米油对照组和海豹油软胶囊0.17、0.33和1.00g·kg-1BW的低、中、高三个剂量组,灌胃给药,每天1次,第30天时考察小鼠负重游泳时间、血清尿素氮、血乳酸和肝糖原水平以及体重变化,并与对照组比较。结果海豹油可延长小鼠负重游泳时间、降低小鼠运动后血清尿素氮水平、增加小鼠肝糖原贮量。可以略降低乳酸曲线下面积,对小鼠体重无显著影响。结论海豹油具有显著的抗疲劳作用,但对体重改变无明显影响。     

大豆卵磷脂对小鼠的抗疲劳和抗氧化作用研究

目的：研究大豆卵磷脂的抗疲劳及抗氧化作用。方法：小鼠经口给予大豆卵磷脂30天后,采用负重游泳实验,观察记录小鼠游泳死亡时间;检测血清尿素氮、肝糖原;测定血清和肝匀浆超氧化物歧化酶（SOD）活性、谷胱甘肽过氧化物酶（GSH—Px）活力、丙二醛（MDA）含量。结果：给予大豆卵磷脂后,与对照组相比,实验组小鼠负重游泳时间明显延长,肝糖原消耗量减少,降低运动后血清尿素氮水平（P〈0．05）;升高小鼠血清和肝匀浆SOD活性及GSH-Px活力,降低MDA的含量（P〈0．05）。结论：大豆卵磷脂具有抗疲劳和抗氧化作用。     

Holographic microscopy provides new insights into the settlement of zoospores of the green alga Ulva linza on cationic oligopeptide surfaces

Interaction of zoospores of Ulva linza with cationic, arginine-rich oligopeptide self-assembled monolayers (SAMs) is characterized by rapid settlement. Some spores settle (ie permanently attach) in a ‘normal’ manner involving the secretion of a permanent adhesive, retraction of the flagella and cell wall formation, whilst others undergo ‘pseudosettlement’ whereby motile spores are trapped (attached) on the SAM surface without undergoing the normal metamorphosis into a settled spore. Holographic microscopy was used to record videos of swimming zoospores in the vicinity of surfaces with different cationic oligopeptide concentrations to provide time-resolved insights into processes associated with attachment of spores. The data reveal that spore attachment rate increases with increasing cationic peptide content. Accordingly, the decrease in swimming activity in the volume of seawater above the surface accelerated with increasing surface charge. Three-dimensional trajectories of individual swimming spores showed a ‘hit and stick’ motion pattern, exclusively observed for the arginine-rich peptide SAMs, whereby spores were immediately trapped upon contact with the surface.     

Enhancement of swimming endurance in mice by highly branched cyclic dextrin

We investigated the ergogenic effect in mice of administering highly branched cyclic dextrin (HBCD), a new type of glucose polymer, on the swimming endurance in an adjustable-current swimming pool. Male Std ddY mice were administered a HBCD, a glucose solution or water via a stomach sonde 10 min before, 10 min after or 30 min after beginning swimming exercise, and were then obliged to swim in the pool. The total swimming period until exhaustion, an index of the swimming endurance, was measured. An ergogenic effect of HBCD was observed at a dose of 500 mg/kg of body weight, whereas it had no effect at a dose of 166 mg/kg of body wt (p < 0.05). The mice administered with the HBCD solution 10 min after starting the exercise were able to swim significantly longer (p < 0.05) than the mice who had ingested water or the glucose solution. The rise in mean blood glucose level in the mice administered with HBCD, which was measured 20 min after starting swimming, was significantly lower (p < 0.05) than that in the mice administered with glucose, although it was significantly higher (p < 0.05) than that in the mice administered with water. The mean blood insulin rise in the mice given HBCD was significantly lower (p < 0.05) than that in the mice given glucose. The mice administered with HBCD 30 min after starting the exercise swam significantly longer (p < 0.05) than the mice who had ingested water, although the enhancement of swimming time was similar to that of the glucose-ingesting mice. The gastric emptying rate of the HBCD solution was significantly faster (p < 0.05) than that of the glucose solution. However, this glucose polymer must have spent more time being absorbed because it has to be hydrolyzed before absorption, reflecting a lower and possibly longer-lasting blood glucose level. We conclude that the prolongation of swimming endurance in mice administered with HBCD depended on its rapid and longer-lasting ability for supplying glucose with a lower postprandial blood insulin response, leading to a delayed onset of fatigue.     

条斑紫菜多糖抗疲劳生物活性研究

主要应用活体动物实验技术,研究了纯化产物紫菜多糖的抗疲劳作用及量效关系。通过紫菜多糖PY-G1不同剂量对小鼠游泳时间、乳酸脱氢酶活性、肌糖原和肝糖原含量等指标的检测,分析了紫菜多糖提高小鼠抗疲劳生物活性功能及其量效关系。实验结果表明,紫菜多糖可显著延长小鼠游泳时间,最高可以提高37%;并且可以使小鼠在游泳前后乳酸脱氢酶含量分别增加35%和37.5%(P<0.05);增加小鼠肌糖原储备量和肝糖原储备量,其肌糖原储备量和肝糖原储备量最高可以分别增加85.6%和86%。实验结果表明,条斑紫菜多糖具有明显提高小鼠抗疲劳生物学活性。     

Oligopeptide-mediated helix stabilization of model peptides in aqueous solution.

Oligopeptide-mediated helix stabilization of peptides in hydrophobic solutions was previously found by NMR and CD spectroscopic studies. The oligopeptide included the hydrophobic amino acids found in its parent peptide and were interposed by relevant basic oracidic amino acids. The strength of the interactions depended on the amino acid sequences. However, no helix-stabilizing effect was seen for the peptides in phosphate buffer solution, because the peptides assumed a random-coil structure. In order to ascertain whether the helix-stabilizing effect of an oligopeptide on its parent peptide could operate in aqueous solution, model peptides EK17 (Ac-AEAAAAEAAAKAAAAKA-NH2) and IFM17 (Ac-AEAAAAEIFMKAAAAKA-NH2) that may assume an alpha-helix in aqueous solutions were synthesized. Interactions were examined between various oligopeptides (EAAAK, KAAAE, EIFMK, KIFME, KIFMK and EYYEE) and EK17 or IFM17 in phosphate buffer and in 80% trifluoroethanol (TFE)-20% H2O solutions by CD spectra. EAAAK had little effect on the secondary structures of EK17 in both buffer and TFE solutions, while KAAAE, which has the reverse amino acid sequence of EAAAK, had a marked helix-destabilizing effect on EK17 in TFE. EIFMK and KIFME were found to stabilize the alpha-helical structure of EK17 in phosphate buffer solutions, whereas KIFMK and EYYEE destabilized the alpha-helical structure of EK17. EIFMK and KIFME had no effect on IFM17, because unexpectedly, IFM17 had appreciable amounts of beta-sheet structure in buffer solution. It was concluded that in order for the helix-stabilizing (1) the model peptide, the alpha-helical conformation of which is to be stabilized, should essentially assume an alpha-helical structure by nature, and (2) the hydrophobicity of the side-chains of the oligopeptide should be high enough for the oligopeptide to perform stable specific side chain-side chain intermolecular hydrophobic interactions with the model peptide.     

新疆野生党参总黄酮体内抗氧化及抗疲劳作用研究

本论文采用对照组及新疆野生党参总黄酮低、中、高三个不同浓度剂量组灌胃小鼠25 d后对其血清与肝脏的超氧化歧化酶( Superoxide Dismutase SOD)活性、丙二醛(Maleic Dialdehyde MDA)含量及肌糖原、肝糖原、血清尿素氮水平等进行测试,并进行负重游泳实验.结果表明:新疆野生党参总黄酮能增强小鼠血清和肝脏的SOD活性,降低MDA的含量,延长小鼠的负重游泳时间,提高肝糖原、肌糖原的储备量,降低小鼠运动后血清尿素氮水平.因而,新疆野生党参黄酮类化合物具明显的抗氧化抗疲劳生理功效.     

APP5肽对糖尿病小鼠学习记忆功能与海马神经元蛋白表达的影响

目的研究APP5肽对糖尿病模型小鼠学习记忆能力及海马神经元蛋白表达的影响。方法用链脲佐菌素诱发小鼠糖尿病模型,应用APP5肽（0.0014 mg/kg）皮下注射治疗,5周后进行Morris水迷宫试验;小鼠脑组织海马做Akt、PI3K、P-CREB、Bcl-2、Bax、CytoC免疫组织化学染色;另一部分鼠脑海马,做Bcl-2、Bax抗体蛋白免疫印记。结果（1）水迷宫试验：糖尿病模型小鼠到达站台游动时间比正常对照组延长（P〈0.01）;而APP5肽皮下注射治疗组较DM组动物分别缩短（P〈0.01）。（2）神经免疫组织化学实验和Western blot：给予APP5肽糖尿病小鼠与对照组小鼠海马组织内神经元表达细胞存活相关蛋白及抗凋亡相关蛋白PI3K、Akt、P-CREB、Bcl-2阳性细胞数相似,明显高于糖尿病小鼠（P〈0.01）;APP5肽给予糖尿病小鼠与对照组小鼠表达凋亡蛋白Bax、cytoC阳性细胞数相似,明显少于糖尿病小鼠（P〈0.01）。Western blot结果相同。结论糖尿病小鼠海马神经元表达细胞存活相关蛋白下降,神经元表达细胞凋亡相关蛋白增加,导致其学习记忆能力下降。APP5肽应用可以使上述蛋白恢复到接近正常,从而改善糖尿病小鼠学习记忆能力。     

Targeted disruption of the PEPT2 gene markedly reduces dipeptide uptake in choroid plexus

The presence of multiple oligopeptide transporters in brain has generated considerable interest as to their physiological role in neuropeptide homeostasis, pharmacologic importance, and potential as a target for drug delivery through the blood-brain and blood-cerebrospinal fluid barriers. To understand further the purpose of specific peptide transporters in brain, we have generated PEPT2-deficient mice by targeted gene disruption. Homozygous PepT2 null mice lacked expression of PEPT2 mRNA and protein in choroid plexus and kidney, tissues in which PepT2 is normally expressed, whereas heterozygous mice displayed PepT2 expression levels that were intermediate between those of wild-type and homozygous null animals. Mutant PepT2 null mice were found to be viable, grew to normal size and weight, and were without obvious kidney or brain abnormalities. Notwithstanding the lack of apparent biological effects, the proton-stimulated uptake of 1.9 microm glycylsarcosine (a model, hydrolysis-resistant dipeptide) in isolated choroid plexus was essentially ablated (i.e. residual activity of 10.9 and 3.9% at 5 and 30 min, respectively). These novel findings provide strong evidence that, under the experimental conditions of this study, PEPT2 is the primary member of the peptide transporter family responsible for dipeptide uptake in choroid plexus tissue.     

New dsDNA binding unnatural oligopeptides with pyrimidine selectivity

Solid phase peptide library screening followed by extension of a lead recognition element for binding to a dsDNA sequence (NF binding site of IL6) using solution phase screening, delivered a new DNA binding peptide, Ac-Arg-Ual-Sar-Chi-Chi-Tal-Arg-CONH2. In the present research, the contribution of the different amino acid side chains to the binding strength of the peptide to dsDNA was investigated using an ethidium bromide displacement test. Based on these results, the lead structure was optimized by deconvolution. Eight new unnatural amino acids were evaluated at two positions of the heptapeptide replacing the Ual-Sar fragment. The strongest dsDNA binding was observed using ([(3-chlorophenyl)methyl]amino)acetic acid (Cbg) and beta-cyclohexyl-l-alanine (Cha) respectively, at those two positions. A 10-fold increase in affinity compared to the Ual-Sar sequence was obtained. Further enhancement of dsDNA binding was obtained with hybrid molecules linking the newly developed peptide fragment to an acridine derivative with a flexible spacer. This resulted in ligands with affinities in the microM range for the dsDNA target (K(d) of 2.1 x 10(-6) M). DNase I footprinting with the newly developed oligopeptide motifs showed the presence of a pronounced pyrimidine specificity, while conjugation to an intercalator seems to redirect the interaction to mixed sequences. This way, new unnatural oligopeptide motifs and hybrid molecules have been developed endowed with different sequence selectivities. The results demonstrate that the unnatural peptide library approach combined with subsequent modification of selected amino acid positions, is very suited for the discovery of novel sequence-specific dsDNA binding ligands.     

不同品系小鼠在三种常见抑郁检测方法中的行为学表现

目的探讨4种不同品系小鼠在3种实验（空场实验、悬尾实验及强迫游泳实验）中的行为学差异,为抗抑郁新药研究中的实验动物选择提供参考。方法利用空场实验检测C57BL/6、BALB/c、ICR、和昆明小鼠的自主活动能力和对新奇环境的探索能力;利用悬尾实验和强迫游泳实验检测它们在应激刺激下的行为绝望状态。结果在空场实验中,BALB/c、ICR和昆明小鼠的运动总路程、运动速度和运动时间明显高于C57BL/6小鼠（P〈0.05）,ICR和昆明小鼠的直立次数也明显高于C57BL/6小鼠（P〈0.05）;悬尾实验C57BL/6小鼠的不动时间显著长于其他3种品系小鼠（P〈0.05）,但是4种品系小鼠在强迫游泳实验中的不动时间差异无显著性。结论 C57BL/6小鼠自发活动量低,对新奇环境的探索能力差,并且在急性应激刺激下容易造成行为绝望,因此C57BL/6小鼠可能适合作为急性应激抑郁模型动物。