Confocal microscopy and biochemical analysis reveal spatial and functional separation between anandamide uptake and hydrolysis in human keratinocytes

The signaling activity of anandamide (AEA) is terminated by its uptake across the cellular membrane and subsequent intracellular hydrolysis by the fatty acid amide hydrolase (FAAH). To date, the existence of an AEA membrane transporter (AMT) independent of FAAH activity remains questionable, although it has been recently corroborated by pharmacological and genetic data. We performed confocal microscopy and biochemical analysis in human HaCaT keratinocytes, in order to study the cellular distribution of AMT and FAAH. We found that FAAH is intracellularly localized as a punctate staining partially overlapping with the endoplasmic reticulum. Consistently, subcellular fractionation and reconstitution of vesicles from membranes of different compartments demonstrated that FAAH activity was localized mainly in microsomal fractions, whereas AMT activity was almost exclusively in plasma membranes. These results provide the first morphological and biochemical evidence to support the view that transport and hydrolysis are two spatially and functionally distinct processes in AEA degradation.Received 11 October 2004; received after revision 24 November 2004; accepted 7 December 2004     

Surface exposure of phosphatidylserine in pathological cells

The asymmetric phospholipid distribution in plasma membranes is normally maintained by energy-dependent lipid transporters that translocate different phospholipids from one monolayer to the other against their respective concentration gradients. When cells are activated, or enter apoptosis, lipid asymmetry can be perturbed by other lipid transporters (scramblases) that shuttle phospholipids non-specifically between the two monolayers. This exposes phosphatidylserine (PS) at the cells outer surface. Since PS promotes blood coagulation, defective scramblase activity upon platelet stimulation causes a bleeding disorder (Scott syndrome). PS exposure also plays a pivotal role in the recognition and removal of apoptotic cells via a PS-recognizing receptor on phagocytic cells. Furthermore, expression of PS at the cell surface can occur in a wide variety of disorders. This review aims at highlighting how PS expression in different cells may complicate a variety of pathological conditions, including those that promote thromboembolic complications or produce aberrations in apoptotic cell removal.Received 26 November 2004; received after revision 3 January 2005; accepted 10 January 2005 Available online 09 March 2005     

肝癌、肝硬化及慢性肝炎患者血脂及载脂蛋白AI、B_（100）水平的变化

本文对３１例肝癌、３０例肝硬化及３１例慢性肝炎患者进行了血清载脂蛋白（ａｐｏ）ＡＩ、Ｂ＿（１００）及血脂的检测，并与６３例健康成人作比较。结果表明：肝癌、肝硬化及慢性肝炎患者血清总胆固醇（ＴＣ）、高密度脂蛋白胆固醇（ＨＤＬ—Ｃ）和ａｐｏＡＩ都显著的降低，与健康对照组比较，均有极显著性差异（Ｐ＜０．００１）；肝癌及肝硬化患者血清甘油三酯（ＴＧ）都呈不同程度的降低（Ｐ＜０．０１和Ｐ＜０．０５）；肝硬化患者的血清ａｐｏＢ＿（１００）也显著的降低（Ｐ＜０．００１）。本文资料提示，在肝脏疾病时检测血脂及ａｐｏＡＩ、Ｂ＿（１００）含量，可以了解肝实质损伤的程度。     

健心1号对超氧自由基与心肌细胞脂质过氧化生成的抑制作用

本文观察到健心1号具有较强的清除超氧自由基能力。并测定健心1号复方制剂的不同浓度,对超氧自由基(O(?))的清除效率。结果表明:随着健心1号浓度的增高,清除O(?)的能力也增强。作者又研究了健心1号对心肌细胞脂质过氧化作用的影响。结果表明:健心1号对~(60)Coγ射线照射和体外温育诱导培养心肌细胞过氧化脂质的生成有明显的抑制作用。     

锯缘青蟹受精过程核相变化的研究

用光镜和组织切片技术研究了锯缘青蟹受精过程核相变化的特征．锯缘青蟹刚排出的成熟卵子为初级卵母细胞．核相处于第1次成熟分裂的中期．在卵子产出后30min内第1极体排出并分裂成两个小极体;第2极体随着受精膜的形成和举起而排放。在卵子产出后50～60min内排出;第1．2极体分别位于受精膜的内外两侧．雄性原核形成早于雌性原核;雌雄原核形成后向卵子中央移动。最后发生联合形成联合核．排卵后的6～7h内。合子核才开始第1次核分裂．锯缘青蟹为数精人卵．单精受精．     

海水和淡水养殖南美白对虾脂质分析与比较

分别取海水养殖的南美白对虾 (海养虾 )和淡水养殖的南美白对虾 (淡养虾 )的肌肉2～ 3g、肝胰腺 1 g,采用 Folch液提取脂肪 ,用气相色谱法 (GC法 )分析测定脂肪的含量和组成。结果表明 :海养虾肌肉含脂肪 3.93% ,比淡养虾肌肉含脂量 2 .79%高 ;海养虾肝胰腺含脂量 1 2 .2 3% ,略低于淡养虾的 1 2 .98%。淡养雄虾的肝胰腺脂肪含量比雌虾高 ,但其肌肉含脂率比雌虾低。在已检测出的脂肪酸中 ,不饱和脂肪酸占大多数 ,而且不饱和多烯酸的含量明显高于不饱和单烯酸 (P <0 .0 1 )。海养虾和淡养虾肌肉脂肪酸含量在 C1 4 :0 ,C1 8:2 n6,C1 8:3 n3 上有显著性差异 (P <0 .0 5) ;肝胰腺脂肪酸含量在 C1 8:2 n6,C1 8:3 n3 ,C2 0 :4n6上有显著性差异 (P <0 .0 5)。南美白对虾与中国对虾、斑节对虾 (肝 )、日本对虾 (肝 )的主要脂肪酸含量在 C1 6:0 ,C1 8:0 ,C1 8:1 n9,C1 8:2 n6,C1 8:3 n3 和 C2 0 :4n6上有较大差别。     

维生素B_6对团头鲂血清生化成分的影响

在精制饲料中添加维素B6投饲团头鲂8周，检测试验鱼血清若干生化成分的变化。结果发现，维生素B6能显著降低血清甘油三酯、总胆固醇和葡萄糖含量，并相应增加血清高密度脂蛋白胆固醇和白蛋白水平及α-淀粉酶活性。分析表明，饲料中添加维生素B6能促进团头纺的血清脂质代谢及其转运，从而避免了血脂积累及营养性脂肪肝的发生。     

Differential effect of silybin on the Fe2+-ADP and t-butyl hydroperoxide-induced microsomal lipid peroxidation

Summary We have observed a differential effect of silybin dihemisuccinate on rat liver microsonal oxygen consumption and on lipid peroxidation induced by NADPH-Fe²⁺-ADP and t-butyl hydroperoxide. These results are ascribed to the antioxidant properties of the flavonoid. The differences observed in the effect of the catalysts may be a consequence of the different capacity of silybin to act as a scavenger of free radicals formed by NADPH-Fe²⁺-ADP or t-butyl hydroperoxide.This research was supported in part by grant B-2019-8412 from Dirección de Investigación y Bibliotecas, Universidad de Chile.