基于~1H核磁共振技术的产后乏情奶牛血浆代谢组学分析

目的应用~1H核磁共振(~1H nuclear magnetic resonance,~1H NMR)技术筛选正常发情奶牛与乏情奶牛血浆中差异表达的代谢物,初步揭示奶牛产后乏情与代谢变化的关系。方法选取年龄、体况、胎次相近的产后60~90 d经产荷斯坦奶牛206头,结合临床表现、直肠检查、B超检查和激素检测结果筛选出发情组(20头)和乏情组(24头)共计44头为实验动物。应用~1H NMR技术对两组奶牛血浆代谢物进行检测,并结合多元统计分析,筛选出两组奶牛血浆中差异代谢物。结果与发情组相比,筛选出的10种差异表达代谢物,即L1[LDL,脂类(低密度脂蛋白)]、L2[VLDL,脂类(极低密度脂蛋白)]、L3(Lipid,脂质)、丙氨酸(Ala)、谷氨酸(Glu)、天冬酰胺(Asn)、肌酸(Crea)、胆碱(Choline)、磷酸胆碱(PC)和甘油磷酸胆碱(GPC),在乏情组奶牛血浆中均表达下调,其参与了能量、氨基酸、脂类以及胆碱等代谢途径。结论筛选出表达下调的差异代谢物,可能导致奶牛处于能量负平衡、脂类代谢异常或脂肪肝状态,从而干扰生殖激素合成与分泌,引发奶牛产后乏情。     

基于液相色谱-质谱联用技术分析鸡胚发育期间血清代谢物的变化

目的应用液相色谱-质谱联用技术(liquid chromatograph-mass spectrometer,LC-MS)分析肉鸡胚胎发育期间血清代谢物的变化。方法将120枚罗氏308肉鸡种蛋随机分为2组,分别于孵化的第14天(E14)和出壳1日龄(H1)收集血清样品。应用LC-MS和高分辨串联质谱SYNAPT G2-XS QTOF,结合主成分分析(principal component analysis,PCA)、偏最小二乘判别分析(partial least squares-discriminate analysis,PLS-DA)、变量投影重要性指标(variable important for the projection,VIP)确定差异代谢产物,并采用代谢物富集分析(metabolite set enrichment analysis,MESA)法分析差异代谢产物涉及的主要代谢途径。结果与E14比较,38个血清代谢物于H1发生显著变化,其中1个显著升高,37个显著下降。差异代谢物主要富集于22个代谢途径中,其中显著富集于蛋白质合成途径的差异代谢产物主要有L-苏氨酸、L-亮氨酸、L-异亮氨酸和L-甲硫氨酸;显著富集于糖异生途径的差异代谢产物主要有L-乳酸、α-酮戊二酸和β-D-葡萄糖;显著富集于缬氨酸、亮氨酸和异亮氨酸降解途径的差异代谢物主要有L-异亮氨酸、L-亮氨酸和脂酰胺。与E14比较,富集于以上代谢途径中的主要差异代谢产物于H1的含量均显著降低。结论鸡胚E14和H1血清代谢物存在显著差异,这些差异代谢物对鸡胚发育有一定影响,可作为日粮添加剂从雏鸡1日龄开始添加,从而满足肉鸡生长发育需要、改善肉鸡生产性能、节约蛋白饲料并降低成本。。     

骨化三醇对实验性自身免疫性脑脊髓炎的治疗作用及相关机制

目的探讨骨化三醇(Calcitriol)对实验性自身免疫性脑脊髓炎(Experimental autoimmune encephalomyelitis,EAE)的治疗作用及相关机制。方法用含200μg髓鞘少突胶质细胞糖蛋白35-55肽段(Myelin oligodendrocyte glycoprotein 33-35,MOG33-35)、250μg结核菌素的50μl弗氏不完全佐剂(IFA)皮内免疫C57BL/6小鼠,并分别于免疫当天和第2天注射百日咳毒素,建立EAE实验性动物模型(EAE组);骨化三醇组从免疫当天起隔日腹腔注射骨化三醇100 ng进行治疗,观察两组小鼠临床评分的差异;于EAE发病高峰期处死小鼠,取脊髓及淋巴结,通过HE及LFB染色观察脊髓中炎细胞浸润及髓鞘脱失;采用流式细胞术检测两组淋巴细胞CD4+T细胞亚型的分布。结果与EAE组比较,骨化三醇组发病延缓且发病较轻,临床评分差异有统计学意义(P<0.05或P<0.01或P<0.001);骨化三醇组较EAE组小鼠脊髓白质炎性细胞浸润明显减少,脱髓鞘斑块明显减轻;骨化三醇组与EAE组相比,Th17细胞亚群明显受到抑制(P<0.05),而Th2和Treg细胞水平明显升高(P均<0.05)。结论骨化三醇可以延缓EAE发病,减轻临床症状及病理改变,并能够通过调节CD4+T细胞亚群平衡,即抑制Th17细胞,上调Th2和Treg细胞水平发挥对EAE的预防和治疗作用。     

胎衣不下奶牛胎盘组织差异表达蛋白的筛选及鉴定

目的筛选胎衣不下奶牛胎盘组织中的差异表达蛋白,并对其鉴定,为研究奶牛胎衣不下的发生机理和治疗提供依据。方法收集胎衣不下奶牛及胎衣正常排出奶牛胎盘组织各5份,应用双向凝胶电泳(two-dimensional polyacrylamidegel electrophoresis,2D-PAGE)技术对胎盘组织中蛋白进行分离,银染显色后获得差异表达蛋白点,并采用基质辅助激光解析电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flight mass spectrometry,MALDI-TOF-MS)技术对其进行鉴定。结果与胎衣正常排出组相比,胎衣不下组奶牛胎牛胎盘中差异表达蛋白点共240个,其中表达上调蛋白点212个,表达下调蛋白点28个;母体胎盘中差异表达蛋白点共214个,其中表达上调蛋白点134个,表达下调蛋白点80个,共鉴定出5种差异表达蛋白。与胎衣正常排出组相比,胎衣不下组奶牛胎牛胎盘中牛血清白蛋白(bovine serum albumin,BSA)、α-烯醇化酶(Alpha enolase)表达下调,谷胱甘肽转移酶(glutathione transferases,GST)表达上调;母体胎盘中膜联蛋白V(Annexin V)、Alpha enolase和膜联蛋白A2(Annexin A2)表达均上调。结论发现的5种差异表达蛋白可能与奶牛胎衣不下的发生发展相关。     

应用蛋白质组学筛选能量负平衡卵巢静止奶牛生物标记物

目的运用蛋白质组学技术筛选能量负平衡卵巢静止奶牛的生物标记物,建立早期诊断标准,并探讨其发病机制。方法应用荧光差异双向凝胶电泳(fluorescence two-dimensional differential gel electrophoresis,2D-DIGE)和基质辅助激光解析离子化飞行时间质谱(matrix-assisted laser desorption/lonization time of flight mass spectrometry,MALDI-TOF-MS),鉴定能量正平衡发情奶牛和能量负平衡卵巢静止奶牛的差异蛋白质。采用生物信息学、蛋白印迹和受试者工作特征(receiver operating characteristic,ROC)曲线分析差异蛋白质,并确定用于早期诊断卵巢静止的生物标志物。结果两组奶牛筛选出12种差异表达蛋白,这些差异蛋白主要参与脂类代谢、维生素代谢、补体凝血级联及过氧化物酶增殖物激活受体(peroxisome proliferator activated receptor-α,PPAR)信号通路,其中α-1-微球蛋白/bikunin前体(alpha-1-microglobulin/bikunin precursor,AMBP)可作为卵巢静止早期诊断的标志物,预警值为4 346.75 ng/L。结论应用蛋白组学筛选出能量负平衡导致奶牛卵巢静止的12种差异表达蛋白,确定了用于早期诊断卵巢静止的生物标志物,为卵巢静止的临床诊断和发病机制奠定了基础。     

胆固醇在高脂高胆固醇诱导非酒精性脂肪性肝炎发生发展过程中的动态作用

目的探讨胆固醇在高脂高胆固醇诱导的非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)发生发展过程中的动态作用。方法将SD大鼠随机分为CON组(正常饮食)、HFC0组(20%脂肪)、HFC1组(20%脂肪+1%胆固醇)、HFC2组(20%脂肪+2%胆固醇)及HFC5组(20%脂肪+5%胆固醇)。饲喂第4、6、8及12周末,采血并取肝脏组织;采用油酸(oleic acid,OA)及OA+低密度脂蛋白-胆固醇(low-density lipoprotein-cholesterol,LDL-C)诱导人肝脏正常细胞(HL-7702)5 d后,构建NASH模型,同时以RPMI1640培养基(含10%FBS)为对照组。分别检测大鼠血浆及HL-7702细胞培养液中丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转氨酶(AST)的含量,大鼠肝脏组织及HL-7702细胞中总胆固醇(total cholesterol,TC)及甘油三酯(triglyceride,TG)的含量;HE及Masson染色观察肝脏组织病理改变;油红O及菲律宾菌素染色观察HL-7702细胞内脂滴及胆固醇含量;Western blot法检测活性n-固醇调节元件结合蛋白-2(n-sterol regulatory element binding protein 2,n-SREBP-2)、低密度脂蛋白受体(low-density lipoproteins receptors,LDLR)及3-羟基3-甲基戊二酰辅酶A还原酶(3-hydroxy-3-methylglutaryl-CoA reductase,HMGCR)的蛋白表达水平。结果动物水平:12周末,与CON组比较,HFC2组、HFC5组血浆中ALT、AST及肝脏组织中TC、TG含量均显著升高(P均<0.05),肝细胞脂肪变性、气球样变性及纤维化病变明显,HFC2组、HFC5组大鼠NASH诱导成功;经Western blot分析,4、6及8周末,HFC2组、HFC5组较CON组LDLR蛋白表达水平均显著升高(P均<0.05),12周末,HFC5组较CON组LDLR蛋白表达水平显著降低(P<0.05);4、6及8周末,各组n-SREBP-2蛋白表达水平与CON组比较差异均无统计学意义(P均>0.05),12周末,HFC2组、HFC5组较CON组n-SREBP-2蛋白表达水平均显著升高(P均<0.05);4、6及12周末各组HMGCR蛋白表达水平与CON组比较差异均无统计学意义(P均>0.05),8周末,HFC5组较CON组HMGCR蛋白表达水平显著降低(P<0.05)。细胞水平:OA+LDL-C组较对照组及OA组细胞内胆固醇含量、n-SREBP-2及HMGCR蛋白表达水平均显著升高(P均<0.05);OA组及OA+LDL-C组较对照组LDLR蛋白表达水平均显著降低(P均<0.05)。结论胆固醇摄入量和摄入时间的长短与NASH肝损伤呈正相关;胆固醇可诱导肝细胞高表达LDLR,促使胆固醇进入肝脏增加,抑制HMGCR调控的内源性胆固醇合成;随着肝内胆固醇堆积增多,肝细胞LDLR表达减少,使肝内胆固醇相对不足,反馈性调节n-SREBP-2及HMGCR表达升高,打破肝脏胆固醇代谢稳态,促进了NASH的发生发展。     

丙型肝炎病毒感染对内皮细胞趋化因子配体1表达的影响

目的探讨丙型肝炎病毒(hepatitis C virus,HCV)感染对肝细胞及血管内皮细胞趋化因子配体1[chemokine(C-X3-C motif)ligand 1,CX3CL1]表达的影响。方法分别以0.5 MOI感染性HCV病毒颗粒(cell-culture-derived infectious HCV,HCVcc)感染Huh7细胞48 h、以不同剂量(0.1、0.2、0.5、1μg)的HCV RNA转染HepG2细胞48 h、以0.5和1.0 MOI HCVcc感染过表达人CD81的HepG2细胞48 h后,抽提各步细胞总RNA,采用Real-time PCR法检测HCV感染肝细胞对胞内CX3CL1 mRNA表达的影响。分别以1.0 MOI HCVcc刺激HUVEC 48 h、以0.1、0.2、0.4、1.0 MOI HCVcc刺激人脑微血管内皮细胞(human brain microvascular endothelial cells,HBMEC)48 h、以0.5 MOI HCVcc刺激Huh7和人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)共培养细胞体系48 h,抽提各步细胞总RNA,采用Real-time PCR法检测HCVcc刺激内皮细胞对胞内CX3CL1表达的影响。结果与未感染细胞对照相比,0.5 MOI HCVcc感染的Huh7细胞中CX3CL1 mRNA水平上调2倍多(P0.05),随着HCV RNA转染HepG2细胞剂量的增加,CX3CL1 mRNA水平随之升高,组间差异有统计学意义(P0.05),0.5和1.0 MOI HCVcc感染过表达CD81的HepG2细胞,胞内CX3CL1 mRNA水平分别上调7.56和13.91倍(P0.05)。与未刺激细胞对照相比,HCVcc刺激HUVEC可引起胞内CX3CL1的mRNA水平上调5倍多(P0.05);与HCVcc未刺激的共培养组相比,与HCVcc感染的Huh7细胞共培养的HUVEC胞内CX3CL1 mRNA水平上调约13倍,HUVEC受HCVcc刺激后,CX3CL1 mRNA水平的上调幅度高于HUVEC单独培养组(P均0.05);与未刺激细胞对照相比,0.1、0.2、0.4和1.0 MOI HCVcc刺激HBMEC可引起胞内CX3CL1 mRNA水平上调1.71、2.37、2.85和3.05倍(P0.05)。结论 HCV感染可引起肝细胞和血管内皮细胞CX3CL1表达上调,HCVcc感染肝细胞释放的细胞因子也是促进内皮细胞CX3CL1表达上调的刺激物,为HCV感染引起肝外疾病产生的机制提供了参考。     

环磷酰胺对MFC荷瘤小鼠影响的1 H NMR代谢组学初步研究

实验采用核磁共振(~1H NMR)代谢组学方法,对MFC荷瘤小鼠和环磷酰胺(CTX)干预MFC荷瘤小鼠的肝脏提取物进行代谢谱分析,结合PCA和OPLS-DA多元数据分析方法,分析差异性代谢物和代谢通路,探索CTX抗肿瘤的作用机制。在肝脏提取物中分析确定了6个潜在的差异代谢物:丙酮酸、羟脯氨酸、肌苷、烟酰胺、胆碱、甘油磷酸胆碱。CTX的抗肿瘤作用可能与调节氨基酸代谢、能量代谢、核酸代谢和脂质代谢等代谢通路有关。     

95．7％高效氟吡甲禾灵原药对Wistar大鼠的13周饲喂毒性

用95.7%高效氟吡甲禾灵原药对Wistar大鼠进行了13周喂饲毒性实验,实验设0、40(低)、200(中)、1000(高)mg/kg饲料4个剂量组,每组雌、雄鼠均为10只.实验结果表明:雄鼠中、高剂量组和雌鼠高剂量组的体重增长受到抑制;雄鼠低、中、高剂量组肝脏、睾丸的相对重最增高,雌鼠中、高剂量组动物肝脏相对重量增高;雄鼠低、中、高剂量组均出现睾丸无精子或精子形成低下、单个肝细胞坏死、小叶中心区肝细胞肿大等症状,而雌鼠中、高剂量组观察到单个肝细胞坏死,小叶中心区肝细胞肿大等症状;雄鼠低、中、高剂量组和雌鼠中、高剂量组动物碱性磷酸酶(ALP)水平增高,雌鼠和雄鼠的中、高剂量组动物丙氨酸氰基转氨酶(ALT)水平均增高,雄鼠高剂毋组总胆同醇水平增高,与对照相比差异显著.根据实验结果,在实验条件下,95.7%高效氟吡甲禾灵原药最大无作用剂量为雄性小于(3.01±0.31)mg/kg·d),雌性(3.10±0.18)mg/(kg·d),靶器官为肝脏和雄性动物的睾丸.     

超声造影在诊断肝细胞性肝癌中的价值

目的应用超声造影技术观察其对肝细胞性肝癌的诊断价值。方法观察组肝细胞性肝癌组患者30例34个结节,对照组肝内胆管细胞癌组患者8例12个结节。观察注射造影剂Sono Vne后2组肿瘤结节的血流灌注特征,并用ImageLab软件分析造影增强期及消退期各参数。结果2组造影特征均为快进快出,2组间的始增时间、峰值时间、增强时间及下降斜率等参数差异均无显著性(P>0.05)。但到达峰值时间时,2组肿瘤结节血流灌注模式的差异具有显著性(P<0.05),肝细胞性肝癌组主要表现为整体型(22/34)或部分型(10/34),肝内胆管细胞癌组主要为周边型(10/12)。结论超声造影技术对肝细胞性肝癌具有良好的诊断价值。     

The Effect of Reactive Dyes on the Main–chain Scission of Wool on Exposure to Light

The extent of the photo–oxidative scission of the main peptide chain of native and reactive–dyed wool has been investigated by a DNP–analysis technique. The total end–group content of native wool, as well as that of dyed wool, is increased sharply by photo–oxidation. This increase is somewhat smaller in native wool than in dyed wool. The changes in individual N–terminal amino–acid contents vary widely in both dyed and native wool. Although the content of N–terminal threonine remains practically unchanged, that of N–terminal glycine increases very sharply, and high increases in aspartic acid, alanine, and glutamic acid also occur. The increase in content of N–terminal serine and valine is smaller.     

UHPLC/MS-Based Serum Metabolomics Reveals the Mechanism of Radiation-Induced Thrombocytopenia in Mice

Radiation-induced thrombocytopenia is a common and life-threatening side effect of ionizing radiation (IR) therapy. However, the underlying pathological mechanisms remain unclear. In the present study, irradiation was demonstrated to significantly reduce platelet levels, inhibit megakaryocyte differentiation, and promote the apoptosis of bone marrow (BM) cells. A metabolomics approach and a UHPLC-QTOF MS system were subsequently employed for the comprehensive analysis of serum metabolic profiles of normal and irradiated mice. A total of 66 metabolites were significantly altered, of which 56 were up-regulated and 10 were down-regulated in irradiated mice compared to normal mice on day 11 after irradiation. Pathway analysis revealed that disorders in glycerophospholipid metabolism, nicotinate and nicotinamide metabolism, sphingolipid metabolism, inositol phosphate metabolism, and tryptophan metabolism were involved in radiation-induced thrombocytopenia. In addition, three important differential metabolites, namely L-tryptophan, LysoPC (17:0), and D-sphinganine, which were up-regulated in irradiated mice, significantly induced the apoptosis of K562 cells. L-tryptophan inhibited megakaryocyte differentiation of K562 cells. Finally, serum metabolomics was performed on day 30 (i.e., when the platelet levels in irradiated mice recovered to normal levels). The contents of L-tryptophan, LysoPC (17:0), and D-sphinganine in normal and irradiated mice did not significantly differ on day 30 after irradiation. In conclusion, radiation can cause metabolic disorders, which are highly correlated with the apoptosis of hematopoietic cells and inhibition of megakaryocyte differentiation, ultimately resulting in thrombocytopenia. Further, the metabolites, L-tryptophan, LysoPC (17:0), and D-sphinganine can serve as biomarkers for radiation-induced thrombocytopenia.     

Some environmental factors affecting free amino acid composition in six varieties of peanuts

This study involved six Spanish type entries (five commercial varieties and a plant introduction) grown in the National Variety Tests in Oklahoma and Georgia under both irrigated and nonirrigated conditions. Significant effects (Georgia vs Oklahoma) were observed on aspartic acid, proline, glycine, valine, isoleucine, peptide, ammonia, and histidine. Significant differences for irrigated vs nonirrigated in the two states for aspartic acid, threonine, proline, glutamic acid, isoleucine, leucine, tyrosine, phenylalanine, peptide, ammonia, and histidine were observed. Significant differences among the six entries were observed for glutamic acid, leucine, tyrosine, phenylalanine, ammonia, histidine, arginine, tryptophan, and total amino acids. None of the treatments produced significant changes in measured amounts of serine, alanine, methionine, and lysine. Significant differences for Georgia vs Oklahoma and irrigated vs nonirrigated for Kjeldahl nitrogen of the whole peanut were noted. Presented at the AOCS Spring Meeting, New Orleans, May 1973. Journal paper 2636 of the Oklahoma Agricultural Experiment Station. ARS, USDA.     

Antioxidative characteristics of oils in ground pork-fat patties cooked with soy sauce

Ground pork-fat patties were cooked alone (control), with NaCl solution, with NaCl solution containing sucrose, with fermented soybean broth, with fermented black soybean broth, and with commercial soy sauce products at 125°C for 2 h. The top-layer oils were then stored at 60°C for periodical determinations of conjugated diene hydroperoxide (CDHP) contents. The fermented broth-cooked and soy sauce-cooked oils were stable against CDHP formation during storage. This supports the customary impression that soy sauce-cooked pork is stable against oxidative rancidity. Analysis of the fatty acid compositions showed the presence of linoleic, linolenic, and arachidonic acids, which are susceptible to oxidation. When the fermented brothcooked oils were extracted with methanol, concentrated, and introduced to the control oils for storage, an estimated antioxidative potency close to that of 2 ppm butylated hydroxyanisole was observed. In comparing free amino acid compositions of the fermented soybean and black soybean broths before and after cooking the ground pork-fat patties, threonine, serine, glutamic acid, alanine, isoleucine, leucine, tryptophan, and tyrosine contents tecreased while proline, valine, histidine, and arginine contents increased.     

微扰理论计算氨基酸和糖水溶液的密度

基于微扰理论并借助于统计缔合流体理论的基本思路,建立了氨基酸和糖水溶液密度的状态方程.计算了甘氨酸、丙氨酸、缬氨酸、氨基丁酸和丝氨酸水溶液体系在4个温度下的密度,以及葡萄糖、果糖、半乳糖、树胶醛糖和木糖水溶液体系在5个温度下的密度.此外采用所建立的方程,不引入任何可调参数,直接对氨基酸在尿素水溶液中的密度进行了预测.关联和预测的结果均令人满意.     

Serum lipids in spontaneously hypertensive rats and sprague-dawley rats fed menhaden oil

Dietary n-3 fatty acids, abundant in fish oil, exert a variety of effects that attenuate cardiovascular disease. In this study, we assessed the effect of fish oil (menhaden oil) on the serum lipid profile in hypertensive and normotensive rats. Spontaneously hypertensive rats (SHR) or Sprague-Dawley rats (SD) were fed either standard powdered diet (L-485), or L-485+5% menhaden oil (MO) or L-485+5% corn oil (CO) from weaning through eight months of age. Systolic blood pressure (BP) was periodically determined on SHR. Serum lipid profiles were performed at eight months on sample taken from the exposed hearts of anesthetized, fasted rats. SHR, compared with SD (diets combined) had significantly lower triaclyglycerols (TG), higher cholesterol (CHOL), higher high density lipoprotein cholesterol (HDL CHOL), higher low density lipoprotein cholesterol (LDL CHOL), and a higher LDL:HDL ratio. Comparison among diets (strains combined) revealed that rats fed MO had the lowest values for TG, CHOL, LDL and LDL:HDL; HDL did no vary with diet. SHR were less responsive to diet-induced changes than were SD; no decrease in TG, LDL or LDL:HDL was observed in SHR, nor was degree of hypertension altered in SHR by the MO or CO diet. In summary, MO is more effective than CO in shifting the lipid profile of rats toward one that is less atherogenic. However, the SD rat is more susceptible to diet-induced lipid modification than is the SHR.     

Chromium electrodeposition using a chromium(iii) glycine complex

A flow plating system was used to investigate chromium metal deposition from an electrolyte based on Cr(iii) and glycine. The Cr(iii) glycine species suitable for chromium deposition was identified. The chemical reactions occurring during electrolyte preparation and during metal deposition are discussed. Chemical reaction sequences for the predominant reactions are suggested. The influences of the chromium ion concentration, temperature and electrolyte velocity on chromium deposition are considered. The optimum conditions for good quality chromium metal deposition are determined.     

A Novel Insight into the Cardiotoxicity of Antineoplastic Drug Doxorubicin

Doxorubicin is a commonly used antineoplastic agent in the treatment of many types of cancer. Little is known about the interactions of doxorubicin with cardiac biomolecules. Serious cardiotoxicity including dilated cardiomyopathy often resulting in a fatal congestive heart failure may occur as a consequence of chemotherapy with doxorubicin. The purpose of this study was to determine the effect of exposure to doxorubicin on the changes in major amino acids in tissue of cardiac muscle (proline, taurine, glutamic acid, arginine, aspartic acid, leucine, glycine, valine, alanine, isoleucine, threonine, lysine and serine). An in vitro interaction study was performed as a comparison of amino acid profiles in heart tissue before and after application of doxorubicin. We found that doxorubicin directly influences myocardial amino acid representation even at low concentrations. In addition, we performed an interaction study that resulted in the determination of breaking points for each of analyzed amino acids. Lysine, arginine, β-alanine, valine and serine were determined as the most sensitive amino acids. Additionally we compared amino acid profiles of myocardium before and after exposure to doxorubicin. The amount of amino acids after interaction with doxorubicin was significantly reduced (p = 0.05). This fact points at an ability of doxorubicin to induce changes in quantitative composition of amino acids in myocardium. Moreover, this confirms that the interactions between doxorubicin and amino acids may act as another factor most likely responsible for adverse effects of doxorubicin on myocardium.     

Insulin Stimulates Lipogenesis and Attenuates Beta-Oxidation in White Adipose Tissue of Fed Rainbow Trout

As lipid deposition tissue in fish, the white adipose tissue (WAT) has important functions related to reproduction and the challenges of long-term fasting. In the study reported here, we infused fish fed a high-carbohydrate diet with two doses of insulin for 5 days in order to explore the effects of this hormone on lipogenesis and beta-oxidation-related enzymes. We demonstrated the presence of some of the main lipogenic enzymes at molecular, protein and activity levels (ATP-citrate lyase and fatty acid synthase). However, while ATP-citrate lyase was unexpectedly down-regulated, fatty acid synthase was up-regulated (at protein and activity levels) in an insulin dose-dependent manner. The main enzymes acting as NADPH donors for lipogenesis were also characterized at biochemical and molecular levels, although there was no evidence of their regulation by insulin. On the other hand, lipid oxidation potential was found in this tissue through the measurement of gene expression of enzymes involved in β-oxidation, highlighting two carnitine palmitoyltransferase isoforms, both down-regulated by insulin infusion. We found that insulin acts as an important regulator of trout WAT lipid metabolism, inducing the final stage of lipogenesis at molecular, protein and enzyme activity levels and suppressing β-oxidation at least at a molecular level. These results suggest that WAT in fish may have a role that is important not only as a lipid deposition tissue but also as a lipogenic organ (with possible involvement in glucose homeostasis) that could also be able to utilize the lipids stored as a local energy source.     

Pyroelectric properties of valine doped TGS single crystals

TGS was grown by a slow cooling technique adding several kinds of dopants (10 and 20 mole% alanine, 10% alanine + LiVO₃, 10% and 20% valine) to an aqueous solution. The temperature dependent pyroelectric coefficient, p and the spontaneous polarization, P_s, of doped-TGS crystals were measured to study the transition temperature, P_max and room temperature pyroelectric coefficient depending on the dopants and to calculate the figure of merit, (p/K), (K is a dielectric constant). Furthermore, several pieces were selected to investigate the positional inhomogeneities of the same sample. Moderate figure of merit (p/K) was obtained in valine doped TGS because of low temperature dielectric relaxation around -10°C, although valine doped TGS has a three times higher pyroelectric coefficient (p = 1.671μC/cm²K) at transition temperature (T_c) than that of alanine doped TGS.