消炎痛对大鼠肝线粒体微粒体^45Ca摄取及膜流动性的影响

我们曾报道消炎痛预处理在大鼠能引起明显的肝保护作用,为了进一步探讨消炎痛肝保护作用的机制,本工作观察了它对大鼠肝线粒体、微粒体钙调节作用及膜流动性的影响。结果表明,经消炎痛整体预处理的大鼠肝线粒体和微粒体的钙摄取及膜流动性均明显增加,但是,将消炎痛直接加入由正常大鼠分离的线粒体或微粒体中,则反而使膜的流动性降低。这些变化可能与消炎痛的肝保护作用有关。     

在原代培养的大鼠肝细胞观察消炎痛的细胞保护作用

我们曾观察到消炎痛预处理能明显减轻四氯化碳和半乳糖胺对大鼠的肝损伤作用,本工作采用原代培养的大鼠肝细胞进一步观察了这一现象。结果表明,经消炎痛整体处理后分离的大鼠肝细胞,在原代培养的条件下,对四氯化碳的损伤仍然具有明显的抵抗作用,表现为细胞内酶的漏出少于对照组。正常大鼠离体肝细胞在原代培养条件下用消炎痛处理,在相当大的剂量和相当长的时间范围内未出现明显的抗损伤作用。结果提示:消炎痛整体处理可使肝细胞本身获得抗损伤的能力,而这种抗损伤能力的产生可能有赖于肝细胞外其它因素的参与。     

大鼠隔—海马通路损伤对海马内递质含量及酶活力的影响

单侧切断大鼠海马缴和部分穹窿可使海马部分去神经。损伤后7d,海马内胆碱能系统中乙酰胆碱(ACh)含量下降72.5%,胆碱乙酰基转移酶(ChAT)活力下降45.7%,胆碱酯酶活力下降52.2%,在单胺能系统中,去甲肾上腺素(NA)含量下降16.3%,多巴胺(DA)含量下降31.3%,5-羟色胺含量下降30.3%。在损伤过程中,海马内氨基酸含量没有改变。实验结果表明,海马缴和穹窿是脑内胆碱能和单胺能传入神经到达海马靶区的部分共同通路。     

大鼠缰核与下丘脑外侧区在调节心血管活动方面的机能联系

电刺激大鼠下丘脑外侧区（LH）,动脉压明显升高,心率加快,在刺激电极同侧缰核（Hb)内微量注射盐酸利多卡因、电刺激LH引起的升压反应可被阻断38.9%,心率增快反应可被阻断44.4%,双侧Hb内微量注射盐酸利多卡因,电刺激LH引起的升压反应可被阻断40.7%,心率增快反应可被阻断41.2% ,单侧或双侧Hb内微量注射人工脑脊液均不能阻断电刺激LH引起的心血管反应。电刺激大鼠Hb,动脉压明显升高,心率无明显改变,在刺激电极同侧LH内微量注射盐酸利多卡因,电刺激Hb引起的升压反应可被阻断63.2%,双侧LH内微量注射盐酸利多卡因,电刺激Hb引起的升压反应可被阻断62.6%,单侧或双侧LH内微量注射人工脑脊液均不能阻断电刺激Hb引起的心血管反应。本实验提示Hb与LH在调节心血管活动方面有协同作用。     

刺激大鼠下丘脑室旁核激活的中脑中央灰质神经元对躯体传入的反应

电刺激大鼠下丘脑室旁核(PVH),在同侧中脑中央灰质(CG)内寻找逆行及顺行反应单位,然后观察它们对躯体感觉刺激的反应。实验结果表明:CG 及邻近网状结构内有10%(32/318)的单位呈逆行反应。逆行传导速度平均为0.37±0.24m/s(均数±标准差);推测这种CG→PVH 投射纤维属于细有髓或无髓神经纤维。这些单位分布于 CG 的腹外侧及背外侧亚核。50%(14/28)的逆行单位对坐骨(胫)神经的强电刺激和夹尾等损伤性刺激起反应,但对触毛或低强度的神经干刺激无明显反应。以上结果表明:外周躯体感觉,特别是损伤性信息传入 PVH 时,CG 是其中枢驿站之一。电刺激 PVH 还能顺行激活7.55(24/318)、抑制0.7%(2/318)的 CG 单位。有69%(18/26)的顺行反应单位对外周躯体神经强电刺激及夹尾起反应。提示 PVH 可能通过影响 CG神经元的活动而参与中枢痛觉的整合。     

拟毛突摇蚊属二新种及一新纪录种记述(双翅目:摇蚊科)

拟毛突摇蚊属Paratrichocladius Santos Abreu 1918隶属于直突摇蚊亚科Ortho-cladinae,迄今全世界已知十余种。Hirvenoja(1973)对本属进行了整理。本文的记载为此属在我国的首次记录。 属征:复眼小眼面间密生细毛,触角比(AR)通常大于1;翅无大毛,腋瓣是多数缘毛;肩陷中等大小,背中鬃多数;无肛尖,抱器基节具一明显的上内突。 本文记述了采自吉林、四川省的2个新种和1个新纪录种。模式标本存南开大学生物学系。     

压脚痛阈测定法的改进和应用

本文介绍一种改进的压脚测痛法。采用电机驱动替代用手挤压橡皮球完成升压过程;通过一个自动的电路切断结构判定抽脚反应,较目视更加客观;用读数保持电路记录压力变化,较直接读取刻度值更加准确,可靠。这些优点,业经电针和吗啡镇痛实验验证。     

黑质升压和弓状核降压效应及二者间的机能联系

本工作用神经元胞体兴奋剂L-谷氨酸钠(Glu)注入箭毒化、人工呼吸大鼠的下丘脑弓状核(AR),引起血压下降,心率减慢;多巴胺(DA)受体激动剂去水吗啡注入AR和Glu注入黑质(SN)均产生升压和加速心率的效应,Glu(i.SN)效应可被DA受体阻断剂氟哌啶醇注入双侧AR阻断;从而证明:(1)AR具有降压、降心率功能;(2)黑质可通过AR内的DA受体对AR降压、降心率效应起抑制作用,而实现其加压、加速心率效应。     

Complex of N-phosphonacetyl-L-aspartate with aspartate carbamoyltransferase. X-ray refinement, analysis of conformational changes and catalytic and allosteric mechanisms

The allosteric enzyme aspartate carbamoyltransferase of Escherichia coli consists of six regulatory chains (R) and six catalytic chains (C) in D3 symmetry. The less active T conformation, complexed to the allosteric inhibitor CTP has been refined to 2.6 A (R-factor of 0.155). We now report refinement of the more active R conformation, complexed to the bisubstrate analog N-phosphonacetyl-L-aspartate (PALA) to 2.4 A (R-factor of 0.165, root-mean-square deviations from ideal bond distances and angles of 0.013 A and 2.2 degrees, respectively). The antiparallel beta-sheet in the revised segment 8-65 of the regulatory chain of the T conformation is confirmed in the R conformation, as is also the interchange of alanine 1 with the side-chain of asparagine 2 in the catalytic chain. The crystallographic asymmetric unit containing one-third of the molecule (C2R2) includes 925 sites for water molecules, and seven side-chains in alternative conformations. The gross conformational changes of the T to R transition are confirmed, including the elongation of the molecule along its threefold axis by 12 A, the relative reorientation of the catalytic trimers C3 by 10 degrees, and the rotation of the regulatory dimers R2 about the molecular twofold axis by 15 degrees. No changes occur in secondary structure. Essentially rigid-body transformations account for the movement of the four domains of each catalytic-regulatory unit; these include the allosteric effector domain, the equatorial (aspartate) domain, and the combination of the polar (carbamyl phosphate) and zinc domain, which moves as a rigid unit. However, interfaces change, for example the interface between the zinc domain of the R chain and the equatorial domain of the C chain, is nearly absent in the T state, but becomes extensive in the R state of the enzyme; also one catalytic-regulatory interface (C1-R4) of the T state disappears in the more active R state of the enzyme. Segments 50-55, 77-86 and 231-246 of the catalytic chain and segments 51-55, 67-72 and 150-153 of the regulatory chain show conformational changes that go beyond the rigid-body movement of their corresponding domains. The localized conformational changes in the catalytic chain all derive from the interactions of the enzyme with the inhibitor PALA; these changes may be important for the catalytic mechanism. The conformation changes in segments 67-72 and 150-153 of the regulatory chain may be important for the allosteric control of substrate binding. On the basis of the conformational differences of the T and R states of the enzyme, we present a plausible scheme for catalysis that assumes the ordered binding of substrates and the ordered release o     

中国钩蛾亚科黄钩蛾属(鳞翅目:钩蛾科)

黄钩蛾属Tridrepana全世界已有32种(Watson,1957),其中包括中国的10种(Watson,1968)。我们手中标本已鉴定10种,其中新增4新种及1新亚种。本文作一全般记录。