高糖对培养大鼠心肌细胞牛磺酸转运的影响及其可能机制

目的：观察不同浓度葡萄糖对细胞牛磺酸(taurine)转运功能的影响。方法：在培养的大鼠心肌细胞上,用^3H标记的牛磺酸测定细胞牛磺酸转运和竞争性定量RTPCR测定细胞牛磺酸转运体(TAUT)mRNA含量。结果：不同浓度葡萄糖(10～30mmol/L)孵育,抑制细胞^3H-牛磺酸转运,呈时间依赖性。与对照组比较,高糖(20mmol／L和30mmol／L)使心肌细胞牛磺酸摄入量显著减少,其^3H-牛磺酸转运的最大速率(Vmax)减少,心肌细胞TAUTmRNA含量较对照组减少。结论：高糖抑制心肌细胞牛磺酸转运,这与TAUT的牛磺酸结合位点减少和TAUT基因转录水平下调有关。     

下丘脑减压区微量注射牛磺酸对血压的影响

实验采用微量注射和荧光分光光度测定的方法,探讨了下丘脑前部减压区牛磺酸对大鼠血压的影响及其可能的机制。结果显示：（１）下丘脑前部减压区微量注射牛磺酸可致大鼠血压降低;（２）侧脑室注射β受体阻断剂心得安可阻断牛磺酸的降压效应。而α受体阻断剂酚妥拉明对牛磺酸的降压效应无明显影响;（３）下丘脑前部减压区注射牛磺酸后,可使下丘脑去甲肾上腺素含量明显增高。     

体外循环下牛磺酸对家兔心肌脂质过氧化的影响

采用家兔微型体外循环模型观察牛磺酸对心肌脂质过氧化的影响,研究提示：体外循环下术后心肌组织脂质过氧化物含量明显增高,而牛磺酸组则接近于正常,说明牛磺酸具有抗心肌脂质过氧化损伤作用。     

牛磺酸对大鼠红细胞的保护作用

牛磺酸对大鼠红细胞的保护作用刘雪芬,莫志贤（第一军医大学南方医院药材科第一军医大学中医系广州５１０５１５）陈晓佳（北京解放军２９２医院药械科１００１６８）牛磺酸广泛存在动物细胞内,对多种有害因素引起的细胞损伤具有保护作用,但对于牛磺酸细胞保护作用的机...     

牛磺酸对急性运动后血清心肌酶的影响

牛磷酸是一种β—氨基酸的亚磺酸类似物,长期被认为是含硫氨基酸的无功能终末代谢产物。80年代开始,Huxtable等对牛磺酸的分布、代谢及其重要而广泛的生物学作用进行了深入的研究,尤其在牛磺酸对心血管系统的保护作用的研究方面,取得了一定的成果。为探讨急性运动时牛磺酸对心脏的作用,我们观察了牛磺酸对急性运动后血清心肌酶活性的影响。     

牛磺酸对学习记忆影响的研究现状

牛磺酸作为一种条件必须氨基酸对学习记忆能力的影响受到越来越多的关注,许多研究证明适量牛磺酸的添加可明显提高大鼠的记忆能力。通过牛磺酸对神经细胞、基因、激素、离子、受体、酶类等的作用,对其影响学习记忆方面的研究现状作出综述。     

牛磺酸对运动大鼠血清脂质的影响

牛磺酸对运动大鼠血清脂质的影响侯香玉,李维根,高云秋（北京医科大学运动医学研究所北京１０００８３）牛磺酸属于含硫的β－氨基酸,是细胞内主要的自由氨基酸,具有调节细胞渗透压、细胞内钙离子浓度和稳定细胞质膜等广泛的生物学效应。为研究牛磺酸对运动机体的作用...     

牛磺酸对HepG2细胞甘油三酯合成的影响研究

本文探讨牛磺酸对HepG2细胞甘油三酯合成的影响,为牛磺酸预防/改善机体高脂状态的深入研究提供参考。在DMEM培养基中添加0.05 mmol/L油酸建立高甘油三酯细胞模型,分别以终浓度为1、5、10、20 mmol/L的牛磺酸处理细胞24、48、72 h,测定细胞内甘油三酯水平;并检测5 mmol/L牛磺酸作用24 h后细胞内固醇调节元件结合蛋白1c(SREBP-1c)及脂肪合成相关酶乙酰辅酶A合成酶(AceCS)、乙酰辅酶A羧化酶(ACC)、脂肪酸合成酶(FAS)、长链酰基辅酶A合成酶1(ACSL1)的蛋白表达水平。1 mmol/L牛磺酸作用72 h,5和10 mmol/L牛磺酸作用24、48、72 h,20 mmol/L牛磺酸作用24和48 h均可使高脂HepG2细胞内甘油三酯水平显著下降(P0.05);5 mmol/L牛磺酸作用24 h,高脂HepG2细胞的SREBP-1c、FAS、ACC、AceCS1、ACSL1表达明显减少(P0.05),磷酸化ACC表达显著增加(P0.05)。结论:牛磺酸通过调控SREBP-1c及其下游靶基因而抑制高脂HepG2细胞脂肪酸/甘油三酯的合成。     

牛磺酸对麦穗鱼抗缺氧能力的影响

在水中溶氧量一定的条件下 ,把麦穗鱼放在不同浓度的牛磺酸水溶液中进行密闭缺氧实验 ,探讨牛磺酸对麦穗鱼抗缺氧能力的影响 ,结果显示 :在 1 4 .5℃～ 1 7.5℃水温下 ,5‰和 1 0‰牛磺酸溶液对麦穗鱼耐缺氧能力有显著增强作用 (p <0 .0 5 )。     

牛磺酸对高糖培养下视网膜Mü ller细胞GFAP和TAUT表达的影响

目的:通过检测高糖培养条件下视网膜Müller细胞神经纤维酸性蛋白(glial fibrillary acid protein,GFAP)和牛磺酸转运蛋白(taurine transporter,TAUT)的表达变化,观察葡萄糖对Müller细胞牛磺酸(taurine)转运功能的影响,探讨牛磺酸对早期糖尿病视网膜病(DR)可能的保护作用。方法:高糖培养大鼠视网膜Mǜller细胞,用免疫细胞荧光化学双染色、Western blotting技术检测不同浓度牛磺酸干预下Müller细胞GFAP及TAUT的蛋白表达。结果:高糖可引起Müller细胞GFAP表达增强,TAUT表达减弱;牛磺酸可减弱高糖引起的Müller细胞GFAP表达增强,TAUT在0．1mmol/L～10mmol/L的牛磺酸干预后表达增强。结论:牛磺酸可以抑制高糖导致的Müller细胞功能改变。     

On the origin of the Hirudinea and the demise of the Oligochaeta

The phylogenetic relationships of the Clitellata were investigated with a data set of published and new complete 18S rRNA gene sequences of 51 species representing 41 families. Sequences were aligned on the basis of a secondary structure model and analysed with maximum parsimony and maximum likelihood. In contrast to the latter method, parsimony did not recover the monophyly of Clitellata. However, a close scrutiny of the data suggested a spurious attraction between some polychaetes and clitellates. As a rule, molecular trees are closely aligned with morphology-based phylogenies. Acanthobdellida and Euhirudinea were reconciled in their traditional Hirudinea clade and were included in the Oligochaeta with the Branchiobdellida via the Lumbriculidae as a possible link between the two assemblages. While the 18S gene yielded a meaningful historical signal for determining relationships within clitellates, the exact position of Hirudinea and Branchiobdellida within oligochaetes remained unresolved. The lack of phylogenetic signal is interpreted as evidence for a rapid radiation of these taxa. The placement of Clitellata within the Polychaeta remained unresolved. The biological reality of polytomies within annelids is suggested and supports the hypothesis of an extremely ancient radiation of polychaetes and emergence of clitellates.     

On the ontogeny of the haptor and the evolution of the Monogenea

Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor