基于Keap1/Nrf2/HO-1通路汉黄芩素7-O-β-D-乙基葡萄糖醛酸苷体外抗氧化应激作用研究

目的 探讨汉黄芩素 7-O-β-D-乙基葡萄糖醛酸苷（WODE）对脂多糖（LPS）诱导的小鼠巨噬细胞（RAW264.7）的抗氧化应激作用及机制。方法 MTS法检测WODE（2.5、5.0、10.0、20.0、40.0、80.0、160.0 μmol·L^-1）对RAW264.7细胞活力的影响；体外培养RAW264.7细胞，WODE（10、20、40 μmol·L^-1）或地塞米松（1 μmol·L^-1，阳性药）预处理1 h，再给予LPS刺激24 h（造模过程不再加药），对照组不加 LPS 和受试物，模型组只给予 LPS 刺激；荧光探针检测胞内活性氧（ROS）水平；Griess反应测定细胞上清液中 NO 生成量；ELISA 检测细胞上清液中肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）的分泌；实时荧光定量 PCR（qRT-PCR）法检测细胞内诱导型一氧化氮合成酶（iNOS）、环氧化酶-2（COX-2）、白细胞介素-1β（IL-1β）、醌氧化还原酶1（NQO-1）、超氧化物歧化酶-1（SOD-1）的mRNA表达水平；Western blotting法检测细胞核因子E2相关因子2（Nrf2）和血红素加氧酶-（1 HO-1）蛋白表达水平；免疫荧光染色法检测细胞内Kelch ECH相关蛋白（1 Keap1）表达水平。结果 与对照组比较，WODE浓度小于40 μmol·L^-1时，细胞存活率没有明显变化；浓度大于80 μmol·L^-1时，细胞存活率下降，但未见统计学差异。与模型组比较，WODE 10、20、40 μmol·L^-1组 ROS水平显著降低（P＜0.01）；20、40 μmol·L^-1 组 NO 释放显著降低（P＜0.05、0.01）；40 μmol·L^-1 组 iNOS mRNA 表 达 水 平 显 著 降 低（P＜0.01）；10、20、40 μmol·L^-1 组 COX-2 和20、40 μmol·L^-1组IL-1β mRNA表达水平显著降低（P＜0.05、0.01）；10、20、40 μmol·L^-1组TNF-α和IL-6的释放受到显著抑制（P＜0.01）；10、20、40 μmol·L^-1组NQO-1 mRNA表达水平显著升高（P＜0.01），40 μmol·L^-1组SOD-1 mRNA表达水平显著升高（P＜0.01）；10、20、40 μmol·L^-1组Keap1蛋白表达水平显著降低（P＜0.01）；10、20、40 μmol·L^-1组HO-1蛋白和mRNA表达水平显著提高（P＜0.05、0.01）；20、40 μmol·L^-1 组 Nrf2 蛋白和 40 μmol·L^-1 组 Nrf2 mRNA 表达水平显著增加（P＜0.01）。结论 WODE 对 LPS 诱导的RAW264.7细胞的氧化应激具有抑制作用，其作用机制可能与调控Keap1/Nrf2/HO-1信号通路相关。     

二妙散对巨噬细胞分化的调控作用研究

目的 研究二妙散对脂多糖（lipopolysaccharide,LPS）诱导巨噬细胞分化的影响。方法 噻唑蓝（methyl thiazolyltetrazolium,MTT）法测定二妙散水煎液对细胞活力的影响;将LPS （100 ng·mL^-1）及不同浓度（0.1,1.0,10 mg·mL^-1）的二妙散水煎液共同作用RAW264.7细胞后,酶联免疫吸附法（enzyme-linked immune sorbent assay,ELISA）检测上清液中肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）、白介素-10（interleukin 10,IL-10）的含量,实时荧光定量PCR （Real-timefluorescent quantitative PCR,qPCR）检测RAW264.7细胞中白介素-1β（Interleukin 1β,IL-1β）,IL-6的mRNA水平,Westernblot检测RAW264.7细胞NOS2的蛋白表达情况。结果 二妙散水煎液在0.01~100 mg·mL^-1内对RAW264.7细胞无明显毒性。与LPS诱导的模型组相比,二妙散水煎液能明显降低细胞上清液中TNF-α的含量（P<0.05）、升高IL-10的含量（P<0.05）,且可显著抑制RAW264.7细胞中M1分化标记物IL-1β、IL-6的mRNA水平（P<0.05）及NOS2的蛋白表达（P<0.05）。结论 二妙散可通过抑制巨噬细胞向M1促炎方向分化,从而发挥抗炎作用。     

注射用丹参多酚酸对MCAO/R大鼠Nrf2/Keap1/HO-1信号通路的影响

目的 采用大鼠大脑中动脉栓塞/再灌注（MCAO/R）模型考察注射用丹参多酚酸（SAFI）对脑缺血再灌注大鼠核因子E2相关因子2（Nrf2）/Kelch样ECH相关蛋白（Keap1）/血红素氧合酶-1（HO-1）信号通路的影响。方法 线栓法构建大鼠MCAO/R模型,于术后24 h进行神经功能评分,将造模成功的大鼠随机分为模型组、丁苯酞（5 mL·kg^-1）组和SAFI低、中、高剂量（5.76、11.51、23.02 mg·kg^-1）组,尾iv给药,连续14 d。考察给药后各组大鼠神经功能缺损评分;ELISA法检测血清超氧化物歧化酶（SOD）、丙二醛（MDA）、脑源性神经营养因子（BDNF）水平;TTC染色法检测脑梗死体积;HE染色观察脑组织病理变化;Western blotting法检测Nrf2、Keap1、HO-1蛋白表达。结果 与模型组比较,SAFI中、高剂量组和丁苯酞组大鼠的神经功能缺损评分显著降低（P＜0.05、0.01） ;SAFI各剂量组和丁苯酞组脑梗死体积显著减少（P＜0.01、0.001）,血清BDNF、SOD水平均显著升高（P＜0.05、0.01、0.001）,MDA水平显著降低（P＜0.05、0.01）,脑组织病理变化明显减轻,水肿减轻; SAFI高、中剂量组及丁苯酞组Keap1、Nrf2、HO-1蛋白表达显著升高（P＜0.05、0.01、0.001）,SAFI低剂量组Keap1、HO-1蛋白表达显著升高（P＜0.01、0.001）。结论 SAFI可以减轻大鼠脑缺血再灌注损伤,可能是通过促进Nrf2/Keap1/HO-1信号通路,抑制氧化损伤实现的。     

苹果多糖的制备及对脂多糖诱导RAW 264.7细胞凋亡的影响

摘 要 目的：观察苹果多糖（AP）对脂多糖（LPS）诱导RAW 264.7细胞凋亡的影响及其机制。方法: 采用水提醇沉法从苹果果渣中提取苹果多糖,并测定其糖含量和分子量。采用流式细胞仪考察AP对LPS诱导RAW 264.7细胞凋亡的作用。采用Western Blot法考察AP对LPS诱导RAW 264.7细胞中Bcl 2、Bax蛋白表达的影响。结果: 经水提醇沉法提取纯化得到苹果多糖的糖含量为91.3%,重均分子量为184613 Da。流式细胞仪检测结果显示,LPS诱导RAW 264.7细胞凋亡明显高于正常对照组（P<0.01）;与LPS组比较,浓度为0.5 mg·mL^-1的AP作用72 h后RAW 264.7细胞凋亡率显著降低（P<0.01）,浓度为1.0 mg·mL^-1的AP作用48,72 h后RAW 264.7细胞凋亡率显著降低（P<0.01）。Western Blot检测结果显示,与正常对照组比较,LPS诱导RAW 264.7细胞中的Bcl 2蛋白在48,72 h表达明显升高,差异具有统计学意义（P<0.01）;与LPS组比较,浓度为1 mg·mL^-1的AP作用后,升高了LPS诱导的RAW 264.7细胞Bcl 2蛋白的表达,降低其Bax蛋白的表达,差异具有统计学意义（P<0.01）。结论:AP抑制LPS诱导RAW 264.7细胞凋亡,其机制可能是通过提高RAW 264.7细胞中Bcl 2蛋白的表达,降低其Bax蛋白表达。     

三七总皂苷调节iNOS-NO-NF-κB信号通路抑制LPS诱导的RAW246.7细胞炎症研究

目的 探讨三七总皂苷（PNS）对脂多糖（LPS）诱导的RAW264.7细胞iNOS-NO-NF-κB信号通路相关分子表达及活性的影响。方法 MTT比色法检测PNS对RAW264.7细胞增殖的抑制作用;不同浓度PNS（25、50、100 μg/mL）干预体外培养LPS诱导的RAW264.7细胞24、48 h后,Griess法检测NO变化;PNS干预24 h后,Western blotting检测iNOS、NF-κB、p-NF-κB、IKKα、p-IKKα、p-ΙκΒα蛋白表达量的变化;PNS干预4 h后,激光共聚焦显微镜检测NF-κB转位入核情况。结果 PNS浓度大于150 μg/mL时,才表现出显著抑制细胞增殖的作用。25、50、100 μg/mL PNS作用于RAW264.7细胞24和48 h后,与模型组比较,NO生成量均显著降低（P<0.001）。50、100 μg/mL PNS作用于RAW264.7 24 h后,iNOS、NF-κB蛋白表达量显著降低,磷酸化蛋白p-NF-κB、p-IKKα、p-ΙκΒα表达水平也显著降低（P<0.01、0.001）。与模型组比较,PNS 25、50、100 μg/mL组核因子p65入核荧光强度显著降低（P<0.01、0.001）。结论 PNS能够显著抑制LPS诱导的RAW264.7细胞iNOS-NO-NF-κB信号通路的活性,降低细胞炎症反应。     

恩格列净及达格列净对棕榈酸诱导的心肌细胞损伤的保护作用及其机制

目的 探讨钠-葡萄糖共转运蛋白-2抑制剂恩格列净（empagliflozin,EMPA）及达格列净（dapagliflozin,DAPA）对棕榈酸（palmitic acid,PA）诱导H9c2心肌细胞损伤的保护作用及其可能机制。方法 采用PA诱导H9c2心肌细胞损伤,CCK-8法筛选PA、EMPA及DAPA的最佳给药浓度;Western blotting检测TLR4、p-AKT、p-mTOR、Nrf2和HO-1的蛋白表达水平;ELISA法检测IL-1β、IL-6和TNF-α的含量;荧光显微镜和流式细胞术检测PA诱导H9c2心肌细胞中ROS水平。结果 PA 100 μmol·L^–1刺激24 h可诱导H9c2心肌细胞存活率明显下降（P<0.01）,IL-1β、IL-6、TNF-α、TLR4蛋白表达、p-mTOR蛋白表达及ROS水平明显增加（P<0.01）,p-AKT、Nrf2和HO-1蛋白表达显著降低（P<0.01）;与模型组比较,经EMPA及DAPA处理后,细胞存活率明显增加（P<0.01）,IL-1β、IL-6、TNF-α、TLR4蛋白表达、p-mTOR蛋白表达及ROS水平明显降低（P<0.05或P<0.01）,p-AKT、Nrf2和HO-1蛋白表达显著上调（P<0.05或P<0.01）。结论 EMPA及DAPA对PA诱导的心肌细胞损伤均具有保护作用,其机制可能与下调TLR4、p-mTOR蛋白表达,增强AKT蛋白磷酸化,激活Nrf2/HO-1通路,抑制ROS的生成有关。     

圣草次苷激活Nrf2信号通路保护H9c2心肌细胞缺氧复氧损伤作用研究

目的 建立大鼠H9c2心肌细胞缺氧/复氧（H/R）损伤模型,考察圣草次苷改善心肌缺血再灌注损伤的作用机制。方法 利用无糖无血清培养基结合厌氧（94%N₂、5%CO₂、1%O₂）处理H9c2心肌细胞4h后,更换新鲜完全培养基再放入正常孵箱复氧24h,制备H/R损伤模型。在造模前12h给予圣草次苷（5、10、20μg·mL^-1）,细胞活力及乳酸脱氢酶（LDH）检测实验中选择灯盏乙素（20μg·mL^-1）作为阳性药,对照组及模型组给予等体积DMSO。MTT法测定细胞存活率;试剂盒检测细胞培养上清液中LDH水平;试剂盒检测细胞内丙二醛（MDA）水平和超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）活力;TUNEL染色检测细胞凋亡;DCFH-DA和JC-1探针分别检测细胞内活性氧（ROS）和线粒体膜电位改变;Western blotting检测核蛋白中转录因子（NF）-E2相关因子2（Nrf2）和总蛋白中血红素氧合酶1（HO-1）、γ-谷氨酰半胱氨酸连接酶（GCL）水平。结果 与对照组比较,H/R损伤诱导的模型组细胞存活率明显下降,凋亡明显增加,LDH水平明显升高,细胞内MDA水平明显升高,SOD、CAT、GSH-Px活力明显降低,ROS释放明显增多,线粒体膜电位明显降低,差异均有统计学意义（P＜0.01）;与模型组比较,圣草次苷可剂量相关性地改善上述变化,其中10、20μg·mL^-1组均差异显著（P＜0.01）。Western blotting结果显示,与对照组比较,模型组细胞Nrf2核转位以及HO-1、GCL表达水平无显著变化;与模型组比较,圣草次苷10、20μg·mL^-1显著增加Nrf2核转位及HO-1、GCL表达水平（P＜0.01）。结论 圣草次苷能够保护H/R诱导的H9c2心肌细胞损伤,其可能通过激活Nrf2抗氧化信号通路,增加细胞内源性抗氧化能力,抑制氧化应激损伤,保护线粒体功能以阻止细胞凋亡的发生。     

甘草内生菌代谢物的抗炎作用

目的 研究甘草内生菌代谢物的体内外抗炎作用。方法 96孔板中接种巨噬细胞RAW264.7培养,模型组加入1 mg·L^-1脂多糖（LPS）,各受试药物组分别加入10,20,40 mg·L^-1甘草水提液浸膏或内生菌发酵物,2 h后再加入LPS1 mg·L^-1培养,检测NO、IL-1β、PGE₂的含量。Wistar大鼠90只,随机分为9组,空白组、模型组、阳性对照组给予生理盐水0.01 mL·g^-1,甘草水煎液组给予甘草水煎液0.95 g·kg^-1,各内生菌代谢物组给予甘草内生菌发酵物0.95 g·kg^-1,每日1次,连续灌胃给药5 d。末次给药后1 h,除空白组外,各组大鼠尾静脉注射1 mg·kg^-1体质量LPS,制备急性肺炎模型,空白组注射等量生理盐水,阳性对照组按5 mg·kg^-1体质量腹腔注射地塞米松给药。6 h后大鼠股动脉取血,检测外周血白细胞计数及血清中TNF-α、IL-6、IL-10的含量。结果 与LPS模型组比较,40 mg·L^-1时,甘草浸膏组、5组内生菌代谢物组（JTZB006、JTZB018、JTZB059、JTZB060、JTZB063）巨噬细胞RAW264.7分泌的NO、PGE₂、IL-1β的含量显著降低（P<0.05或P<0.01）;与同一质量浓度（40 mg·L^-1）的甘草浸膏组比较,JTZB006、JTZB060组巨噬细胞RAW264.7分泌的PGE₂的含量显著降低（P<0.05）。与模型组比较,阳性对照组、甘草水煎液组、3组内生菌代谢物组（JTZB006、JTZB060、JTZB063）大鼠外周血中白细胞数量及血清中TNF-α、IL-6的含量均显著降低,IL-10的含量显著升高（P<0.05或P<0.01）;与甘草水煎液组比较,JTZB006、JTZB060、JTZB063组IL-10的含量显著升高（P<0.05或P<0.01）。结论 3株甘草内生菌代谢物（JTZB006、JTZB060、JTZB063）对LPS诱导的炎症模型具有体外及体内抗炎作用。     

獐牙菜苦苷的抗炎活性及其对NF-κB通路相关因子p65和IKK-α表达的影响

目的 观察獐牙菜苦苷（Swertiamarin）的抗炎活性以及对核转录因子-κB（NF-κB）通路的调控作用。方法 采用脂多糖（LPS）诱导小鼠巨噬细胞RAW264.7构建体外炎症模型,CCK-8法观察獐牙菜苦苷对细胞活性的影响,ELISA法检测其对炎症相关因子肿瘤坏死因子-α（TNF-α）、白介素-6（IL-6）表达的影响,RT-PCR法测定其对NF-κB通路相关因子p65和IKK-α的mRNA表达的影响。结果 100 μg·mL^-1獐牙菜苦苷能降低细胞存活率,3.125~50 μg·mL^-1浓度对细胞存活率无影响;25~50 μg·mL^-1獐牙菜苦苷能降低炎症相关因子TNF-α及IL-6的释放;12.5~50 μg·mL^-1獐牙菜苦苷能抑制p65的mRNA表达,50 μg·mL^-1獐牙菜苦苷能抑制IKK-α的mRNA表达。结论 獐牙菜苦苷对LPS诱导的炎症模型中TNF-α、IL-6的生成具有抑制作用,其机制可能与抑制NF-κB通路相关因子p65、IKK-α的表达有关。     

桑黄水煎液对D-半乳糖衰老模型小鼠的抗氧化作用

目的 观察桑黄水煎液对D-半乳糖诱导小鼠氧化损伤的保护作用,并探讨其保护作用的可能机制。方法 ①ICR小鼠分为正常对照组,桑黄水煎液低、中、高剂量（2,6,12 g·kg^-1）组,连续给药15 d。②ICR小鼠分为正常对照组、模型组、维生素E组（50 mg·kg^-1）,桑黄水煎液低、中、高剂量（2,6,12 g·kg^-1）组,小鼠颈背部皮下注射D-半乳糖（120 mg·kg^-1）造成亚急性衰老模型,按分组连续给药42 d。比色法测定小鼠肝脏及血清中丙二醛（MDA）含量和抗氧化酶活力,如超氧化合物歧化酶（SOD）、总抗氧化能力（T-AOC）、过氧化酶（POD）等。Western blot检测肝脏中核因子E2相关因子2（Nrf2）和血红素氧合酶1（HO-1）的表达。结果 桑黄水煎液对正常小鼠和D-半乳糖诱导小鼠体质量及脏器指数均无明显影响。桑黄水煎液可显著提高正常小鼠肝脏中T-AOC和SOD酶活力（P<0.01,P<0.05）。各剂量桑黄水煎液可显著提高衰老模型小鼠血清中T-AOC,降低MDA含量（P<0.01,P<0.05）,同时中剂量增强肝脏中SOD （P<0.05）和POD酶活力（P<0.01）,中、高剂量均上调肝脏中Nrf2和HO-1蛋白表达水平（P<0.01）。结论 桑黄水煎液具有提高正常小鼠抗氧化能力和改善D-半乳糖致小鼠氧化损伤作用,此作用可能是通过调节Nrf2/HO-1途径增加体内抗氧化酶的活性,减少过氧化脂质的生成,进而提高机体抗氧化能力。     

Cerebral metabolism of [3H]-p-chloroamphetamine

The time-dependent metabolism of intraventricularly administered $\text{[}{}^3\text{H}\text{]-p-}\text{chloroamphetamine}$ was followed. The parent compound and its metabolites were recovered by high pressure liquid chromatography and characterized by high pressure liquid chromatography, thin-layer chromatography, and gas chromatography-mass spectrometry. By 4 hr after injection, two major toluene-soluble metabolites were present in brain. Their biological half-lives were different from the parent compound. On the basis of their analyses, one of the metabolites is p-chloronorephedrine, the other (P₃) is as yet unidentified. Pretreatment with Lilly 110140 prevented or markedly reduced the synthesis of both p-chloronorephedrine and P₃. Iprindole prevented the synthesis of p-chloronorephedrine. The P₃ appeared first in the brain then in the liver, suggesting that both of these organs can metabolize p-chloroamphetamine to this compound. The metabolites were recovered primarily from the nuclear and microsomal fractions following subcellular fractionation of the brain, with small quantities present in the synaptosomal fraction. The level of metabolites was higher in the brainstem than in the neocortex. Glutathione, administered simultaneously with p-chloroamphetamine either intraventricularly or intraperitoneally failed to alter the toxicity of p-chloroamphetamine.     

Clevudine University of Georgia/Abbott/Bukwang/Triangle/Yale University

The pyrimidine analog, clevudine (L-FMAU: 2'-fluoro-5-methyl-beta-L-arabinofuranosyluridine) is a potent antihepatitis B virus (HBV) and anti-Epstein-Barr virus (EBV) agent, discovered by researchers at the University of Georgia, in collaboration with Yale University and Bukwang. Bukwang transferred its technology to Triangle Pharmaceuticals in 1998 together with a license to develop clevudine worldwide except Korea [279649], [281942]. In June 1999, Triangle and Abbott Laboratories entered into a strategic alliance to copromote antiviral products including L-FMAU [326798]. In September 2000, Triangle Pharmaceuticals Inc initiated a 30-day phase I/II evaluation of clevudine in HBV-infected patients [381755]. Clevudine is a much less toxic derivative of the toxic agent P-D-FMAU. The mechanism of action of clevudine is not yet clear, but the agent induces a rapid decrease in HBV nucleic acid as doses increase from 0.3 to 10 mg/kg [319145]. It is believed that the target for clevudine lies in the viral replication mechanism. Clevudine is phosphorylated to the triphosphate form intracellularly. This is removed slowly from the cells, thus exerting a sustained inhibitory antiviral activity [178173], [320720], [320721].     

Spotlight from the American Society for Preventive Cardiology on Key Features of the 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guidelines on the Management of Blood Cholesterol

The 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol retains focus on recommendations for statin treatment in the original four statin-eligible groups [those with atherosclerotic cardiovascular disease (ASCVD), diabetes, low-density lipoprotein cholesterol (LDL-C) ≥ 190 mg/dL, and higher risk primary prevention] without the use of treatment initiation or target LDL-C levels from the earlier 2013 American College of Cardiology/American Heart Association (ACC/AHA) guideline, but has several new features. First, patients with primary prevention are divided into those who are at low (< 5%), borderline (5% to < 7.5%), intermediate (7.5% to < 20%), and high (≥ 20%) risk based on the ASCVD risk estimator. Moreover, the new guideline goes further to consider a wider range of factors [now called “risk enhancers”—premature family history of ASCVD, persistently high LDL-C, chronic kidney disease (CKD), metabolic syndrome, conditions specific to women, inflammatory diseases, and high-risk ethnicities] that can be used to better inform the treatment decision. Moreover, more detailed recommendations on how the results of coronary calcium scanning can be used to inform the treatment decision are provided, including how it may be used to “de-risk” certain patients for delaying or avoiding the use of statin therapy. There are also specific sections for cholesterol management in other patient subgroups including women, children, certain ethnic groups, those with CKD, chronic inflammatory disorders and HIV, as well as discussion on the management of hypertriglyceridemia. Importantly, for persons with known ASCVD, a distinction is made for those who are at “very high risk” based on having had two major ASCVD events or one major event and two or more other high risk conditions, such as diabetes or other major risk factors, or bypass surgery or percutaneous intervention. Finally, the concept of a threshold LDL-C for initiating a non-statin therapy (after considering highest tolerated statin dosage) is provided, with ezetimibe recommended as the key non-statin to be added if the LDL-C still remains ≥ 70 mg/dL for all ASCVD patients, and in those who are at “very high risk”, further consideration for using a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor. While the new guideline does have greater detail (and arguably, complexity), the refinements provide a strategy for guiding the clinician to target both statin and non-statin therapy to those most likely to derive benefit.     

Pitavastatin Nissan/Kowa Yakuhin/Novartis/Sankyo

Pitavastatin (nisvastatin) is an HMG CoA reductase inhibitor being developed jointly by Nissan, Kowa Kogyo, Novartis and Sankyo for the potential treatment of atherosclerosis and hyperlipidemia.     

N-Nitroso-N-Methyldodecylamine and N-Nitroso-N-Methyltetradecylamine in household dishwashing liquids

Eleven household dishwashing liquids and four household surface cleaners were analysed for N-nitroso-N-methyldodecylamine and N-nitroso-N-methyltetradecylamine by gas chromatography with detection using a Thermal Energy Analyzer. Both nitrosamines were found in three of the dishwashing detergents and one of the surface cleaners. [1-¹⁴C]-N-Nitroso-N-methyldodecylamine was used to determine recoveries, which were between 65 and 88%. Levels of N-nitroso-N-methyldodecylamine ranged from 112 to 661 ppb and those of N-nitroso-N-methyltetradecylamine from 46 to 151 ppb. A simple method was developed to screen the products for N,N-dimethyldodecylamine-N-oxide, a surfactant ingredient suspected of being the source of these nitrosamines. By application of this method it was established that all of the products formulated with this amine oxide contained these two nitrosamines, whereas in products that did not contain this ingredient, these nitrosamines were not detected.     

PROTON AND POTASSIUM TRANSPORT BY H+/K+-ATPases

1. H⁺/K⁺-ATPases are members of the P-type ATPase multigene family. The prototypical H⁺/K⁺-ATPase is the protein that acidifies gastric luminal contents. The physiological and pharmacological significance of this pump has led to a detailed investigation of its biochemistry and molecular and cell biology. 2. Recently, a number of closely related H⁺/K⁺-ATPase isoforms have been discovered. These isoforms are present in organs other than the stomach, including the colon and kidney, where they contribute to acid—base and potassium homeostasis. The structure, expression and physiological roles of the gastric H⁺/K⁺-ATPase and other isoforms are reviewed.     

INTERACTIONS OF Na+, H2O2 AND THE Na+-Ca2+ EXCHANGER STIMULATE Ca2+ RELEASE IN CK1.4 CELLS

1. The present study aimed to demonstrate that interactions of cations, hydrogen peroxide (H₂O₂) and the Na⁺-Ca²⁺exchanger stimulate Ca²⁺ release and oscillations of cytosolic Ca²⁺ [Ca²⁺]i in non-transfected Chinese Hamster Ovary (CHO) C1 cells and in transfected CHO (CK1.4) cells that contained an expression vector coding the Na⁺-Ca²⁺ exchanger sequence. 2. The [⁴⁵Ca²⁺] uptake assay, fura-2 fluorescence imaging and 2² and 2³ factorial orthogonal statistics provide comparative, direct, efficient, quantitative and transient methods to delineate the effects of such interactions on Ca²⁺ influx, Ca²⁺release and [Ca²⁺]i in C1 and CK1.4 cells. 3. In contrast to the control of either Na⁺-, Ca²⁺- or H₂O₂-free or CI cells, an elevated [⁴⁵Ca²⁺] uptake was induced by Ca²⁺, Na⁺ and H₂O₂ individually and in combination, intracellular Ca²⁺ release was activated by H₂O₂ and by combinations of either H₂O₂ and Na⁺, H₂O₂ and the Na⁺-Ca²⁺ exchanger, Na⁺ and the Na⁺-Ca²⁺ exchanger or by H₂O₂, Na⁺ and the Na⁺-Ca²⁺ exchanger and a rise in [Ca²⁺]i was triggered by H₂O₂, Na⁺ and a combination of Na⁺ and the Na⁺-Ca²⁺exchanger. 4. These results indicate that interactions between H₂O₂, Na⁺ and the Na⁺-Ca²⁺ exchanger stimulate intracellular Ca²⁺mobilization via Ca²⁺-induced Ca²⁺ release mechanisms, ATP-activated G-protein coupled P_2y-purinoceptor-sensitive pathways, Na⁺-Ca²⁺ exchanger-mediated Ca²⁺ influx and cation-π interaction (a strong non-covalent force between the cation and the π face of an aromatic structure in the transmembrane protein). 5. The present findings provide important clues for understanding Ca²⁺ signal transduction mechanisms from the plasma membrane to the endoplasmic reticulum.     

Amlodipine/Valsartan/Hydrochlorothiazide

Amlodipine/valsartan/hydrochlorothiazide (HCTZ) is a fixed-dose combination of the well established antihypertensive agents amlodipine (a calcium channel antagonist), valsartan (an angiotensin II receptor antagonist), and HCTZ (a thiazide diuretic). In patients with moderate or severe hypertension, triple combination therapy with amlodipine + valsartan + HCTZ produced significantly greater reductions from baseline in mean sitting systolic and diastolic BP (msSBP and msDBP) than either valsartan + HCTZ, amlodipine + HCTZ, or amlodipine + valsartan in a large, 8-week, randomized, double-blind, multinational, phase III trial. Furthermore, the proportion of patients achieving overall BP control at endpoint was significantly greater with the triple combination regimen than with any of the dual regimens, with significantly more triple combination recipients achieving msSBP and msDBP control at each assessment throughout the trial. Subgroup analyses of this study suggested that amlodipine + valsartan + HCTZ was generally more effective in reducing BP and providing overall BP control than the dual combination therapies, irrespective of age, race, gender, ethnicity, or hypertension severity. Several smaller studies provide data that support the efficacy of amlodipine + valsartan + HCTZ in patients whose BP is inadequately controlled with amlodipine + valsartan, amlodipine + HCTZ, or valsartan + HCTZ dual combination therapy. Treatment with amlodipine + valsartan + HCTZ for up to 8 weeks was generally well tolerated in the large, phase III trial, with most adverse events being transient and of mild to moderate severity.     

EFFECTS OF THE OPIOID PEPTIDES [MET5]ENKEPHALIN-ARG6-PHE7 AND [MET5]ENKEPHALIN-ARG6-GLY7-LEU8 ON CHOLINERGIC NEUROTRANSMISSION IN THE RABBIT ISOLATED ATRIA

1. The effect of the opioid peptides [Met5]enkephalin-Arg6-Phe7 (MEAP) and [Met5]enkephalin-Arg6-Gly7-Leu8 (MEAGL) were compared with those of [Leu5]enkephalin and [D-Ala2,Met5]enkephalinamide (DAME) on cholinergic neurotransmission in the rabbit isolated atria. 2. Rabbit isolated atria had a resting rate of 190 beats/min. In the presence of the beta-adrenoceptor antagonist propranolol (0.3 mumol/l), atria responded to electrical field stimulation with a cholinergically mediated negative chronotropic response. The opioid peptides had no effect on the resting rate, but inhibited the negative chronotropic response to field stimulation. The IC50 values for inhibiting the cholinergic responses were 1.4 mumol/l for [Leu5]enkephalin (LE), 1.4 mumol/l for MEAP, 1.3 mumol/l for MEAGL and 0.2 mumol/l for DAME. Responses of a similar magnitude to exogenous acetylcholine were unaffected. 3. Thus, MEAP, MEAGL and LE had similar potencies but DAME was about seven times more potent in inhibiting cholinergic neurotransmission in the rabbit isolated atria. The site of inhibition appears to be prejunctional.