Involvement of phospholipase A2 in norepinephrine release from synaptosomes isolated from rat cerebral cortex

Phospholipase A₂ added directly to superfused [³H]norepinephrine-labeled synaptosomes could cause the release of neurotransmitter molecules. Chloroquine and quinacrine, which block the action of phospholipase A₂, inhibited either the phospholipase A₂-stimulated or the high potassium-stimulated release of [³H]norepinephrine from synaptosomes. Only quinacrine blocked the high potassium-stimulated influx of Ca²⁺. It appears that during stimulation of synaptosomes, Ca²⁺ influx leads to the activation of phospholipase A₂, which in turn, hydrolyzes membrane phospholipids in situ. The formation of lysophospholipids may alter the microenvironment and the physicochemical properties of membranes, resulting in the release of neurotransmitter through exocytosis.     

依兰花精油的香气成分

云南省西双版纳产依兰油,用Finnigan-4510型毛细管气相色谱/质谱/计算机联用方法进行了化学成分分析,共分离检出了50个成分,鉴定了其中22个成分,占全精油的95.27％。主要成分为:β-丁香烯(33.00％),γ-穆罗烯(19.82％)。α-(艹律)草烯(7.69％),乙酸香叶酯(6.21％),香柠檬烯(5.40％),苯甲酸苄酯(5.33％),金合欢醇(4.75％),金合欢烯(3.29％),香叶醇(2.48％),对甲酚甲醚(2.41％)。并讨论了如何提高国产依兰油质量的问题。     

蝮蛇毒抗凝血活酶组份及几种蛇毒粗毒对人红细胞和血小板的作用

蝮蛇毒抗凝血活酶组分及蝗蛇毒、圆斑蝰蛇毒和眼镜蛇毒粗毒,不仅能够水解血浆中的磷脂,而且还能水解完整人红细胞膜和完整人血小板膜上的磷脂。但是五步蛇毒和金环蛇毒粗毒却不能水解完整人血小板膜上的磷脂。 扫描电镜观察表明,由于抗凝血活酶组份和几种蛇毒粗毒的作用,人红细胞和人血小板的形态发生了巨大的变化;人红细胞由正常的双圆盘形变成带刺的小球,人血小板的外形变成蜂窝状。     

Metabolic relationship between arachidonate activation and its transfer to lysophospholipids by brain microsomes

Evidence is presented to indicate a metabolic relationship between arachidonic acid activation and its transfer to lysophospholipds by brain microsomes. Thus, in the presence of 1-acylglycerophosphocholines or 1-acyl-glycerophosphoinositols, the activation of labeled arachidonate to its acyl-CoA was enhanced, and the acyl-CoA formed was, in turn, transferred to the lysophospholipids to form the respective diacyl-glycerophospholipids. The coupling effect seems to pertain mainly to the lysophospholipids which are good substrates of the acyltransferase. Other lyso-compounds were either not effective or inhibitory to the arachidonate activation process. The activation-transfer activity mediated by the fatty acid ligase and acyltransferase could be dissociated by Triton X-100, which apparently stimulated the acyl-CoA ligase activity but inhibited the acyltransferase. These results suggest that fatty acid ligase and acyltransferase are located in close proximity within the membrane domain. The existence of a close metabolic relationship between these two enzymic reactions is important for maintaining a dynamic equilibrium between the free fatty acids and the membrane phospholipids. The mechanism is also useful in regulating the cellular acyl-CoA and lysophospholipid metabolism, because both compounds have membrane perturbing properties when present in excessive quantity.     

“同时蒸馏-萃取”分析茉莉花香成分

用一种经过改进的“同时蒸馏-萃取”仪提取了茉莉花的香成分,以 GC/MS 和 Kovats保留指数法鉴定了提取物中的28个化学成分。主要成分为:芳樟醇、乙酸苯甲酯、顺-石竹萜烯、榧烯醇、苯甲酸顺-3-己烯酯、邻氨基苯甲酸甲酯、二十三烯-11及吲哚。讨论了鲜花香成分和植物精油的采集与分析方法。     

用PFU法研究微型生物群集过程中数据的处理

根据MacArthur-Wilson的岛屿区系平衡模型S_t=S_(eq)(1-e~(GT)),可以从野外生态效应试验和室内毒性试验中,提出3个功能参数(S_(eq)、G、t_(90％))进行比较。本文提出两种计算方法:复合梯形法和最小二乘法,后者已在计算机上实现了BASIC计算程序。从数学理论上论证,最小二乘法误差较小,但如果实验布局合理,两种计算方法能得到十分一致的结果。实验模型是否符合理论模型,可以用统计学上的拟合差异度检验法来检验。     

成人腹泻轮状病毒的提纯及其高价免疫血清的制备

本文采用交叉免疫电泳技术,首先提纯了成人腹泻轮状病毒(Adult DiarrhoeaRotavirus简称:ADRV),并经电镜确认,用作免疫抗原,首次制备了高价兔与豚鼠抗ADRV血清和小鼠抗ADRV腹水,其特异性经交叉免疫电泳和对流免疫电泳鉴定,其效价经酶联免疫吸附试验(ELISA)检测均在1:2,000以上。     

湖北菱科的数量分类研究[Ⅱ]

引言菱科(Trapaceae)植物为一年生水生浮叶草本,常见于湖泊,池塘及沟渠中。全世界约有70余种,主要分布于旧大陆的温带、亚热带地区,亦见于热带地区,如印度,东南亚及非洲,后来被引进美洲大陆和澳大利亚。中国有5至10种及其栽培种。菱科为一单属科。自林奈时期以来,菱科的分类学研究一直是一个富有探索性的问