不同介入时间和不同疗程高压氧治疗对脑出血模型大鼠动物学行为及促血管新生因子表达的影响

摘要 目的：探讨不同介入时间和不同疗程高压氧治疗对脑出血大鼠动物学行为及促血管新生因子表达的影响。方法：240只SD大鼠随机分为假手术组、脑出血组、高压氧组,每组各80只。采用胶原酶诱导建立脑出血大鼠模型,建模成功后根据高压氧介入时间分为6 h介入组、1 d介入组、2 d介入组、3 d介入组等亚组。分别治疗1周、2周、3周、4周,采用Longa评分法、平衡木评分法、Berderson评分法评估大鼠动物学行为,采用qRT-PCR检测大鼠脑组织血管内皮生长因子（VEGF）、缺氧诱导因子-1α（HIF-1α）mRNA表达。结果：不同介入时间、不同疗程,脑出血组、高压氧组脑出血大鼠动物学行为评分、脑组织VEGF mRNA与HIF-1α mRNA表达均高于假手术组（P<0.05）。治疗1周、2周、3周、4周,不同介入时间高压氧组脑出血大鼠动物学行为评分低于脑出血组,脑组织VEGF mRNA、HIF-1α mRNA表达高于脑出血组（P<0.05）。高压氧介入时间越早,治疗疗程越长,脑出血大鼠动物学行为评分越低,脑组织VEGF mRNA、HIF-1α mRNA表达越高,差异均有统计学意义（P<0.05）。结论：高压氧治疗能够改善脑出血大鼠动物学行为、促进促血管新生因子表达,且以脑出血后6 h介入、疗程4周效果最佳。     

小檗碱对牙周炎大鼠的细胞因子水平、氧化应激和炎症性骨溶解的实验研究

摘要 目的：研究小檗碱对牙周炎大鼠的治疗效果，并探讨小檗碱治疗对牙周炎大鼠牙龈组织炎症细胞因子、氧化应激和炎症性骨溶解的影响。方法：45只SD大鼠被随机分为三组，即对照组、模型组和小檗碱治疗组。模型组和小檗碱治疗组大鼠通过涂抹牙周致病菌建立牙周炎模型，对照组大鼠涂抹生理盐水。小檗碱通过灌胃给予小檗碱进行治疗，对照组和模型组大鼠给予等量生理盐水。小檗碱治疗8周后，安乐死各组大鼠通过ELISA试剂盒测定各组大鼠牙龈组织中前列腺素E2（PEG2）、白介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）、丙二醛（MDA）、过氧化氢脂质（LPO）、过氧化氢酶（CAT）、核因子-kB活化受体（RANKL）和骨保护素（OPG）含量。结果：与牙周炎模型组大鼠比较，小檗碱治疗组牙周炎大鼠牙龈指数和附着水平均显著降低（P<0.05）。小檗碱治疗8周后，牙周炎大鼠模型牙龈组织PEG2, IL-1β, TNF-α和IL-6等炎症细胞因子水平均显著下降（P<0.05），氧化应激指标MDA和LPO均显著下降（P<0.05），抗氧化应激指标CAT含量显著上升（P<0.05）。此外，小檗碱还显著降低牙周炎大鼠牙龈组织RANKL含量和RANKL/OPG比值（P<0.05），而显著提高牙周炎大鼠牙龈组织OPG含量（P<0.05）。结论：小檗碱对牙周炎大鼠具有较高的治疗效果，其机制可能与小檗碱治疗可降低牙周炎大鼠牙龈组织炎症细胞因子含量，降低氧化应激水平和缓解炎症性骨溶解有关。     

姜黄素衍生物减缓大鼠糖尿病周围神经病变进展的作用及其机制研究

摘要 目的：探讨姜黄素衍生物减缓大鼠糖尿病周围神经病变（DPN）进展的作用及其机制。方法：30只健康成年雄性SD大鼠随机分为3组，每组10只；构建链脲佐菌素（STZ）诱导的DPN大鼠模型；研究组1按10 mg/kg体重喂养10 μM的姜黄素衍生物；研究组2按10 mg/kg体重喂养100 μM的姜黄素衍生物；对照组喂养同等量的生理盐水。利用Von Frey电子测痛仪检测各组大鼠痛觉机械戒断阈值（MWT）。采用实时定量聚合酶链反应（qRT-PCR）和蛋白免疫印迹试验检测AMPK、mTOR mRNA和蛋白表达水平。最后测定活化剂AICAR处理的RSC96细胞中mTOR的表达水平。结果：喂养姜黄素衍生物大鼠的痛觉机械戒断阈值（MWT）随时间推移逐渐降低，与对照组相比，研究组1大鼠的MWT显著降低，而研究组2大鼠的MWT也显著低于研究组1，差异均有统计学意义（P＜0.05）。与对照组相比，研究组1的AMPK mRNA和蛋白表达水平显著升高，mTOR mRNA和蛋白表达水平表达显著降低（P＜0.05）；而研究组2的AMPK mRNA和蛋白表达水平显著高于研究组1，mTOR mRNA和蛋白表达水平显著低于研究组1，差异均有统计学意义（P＜0.05）。使用活化剂AICAR处理RSC96细胞后，活化剂AICAR组的mTOR mRNA和mTOR蛋白表达水平明显低于非活化剂组，差异有统计学意义（P＜0.05）。结论：姜黄素衍生物可能通过AMPK调节mTOR信号通路改善DPN，其可能具有潜在的治疗DPN的能力。     

羌活地黄汤对佐剂性类风湿关节炎大鼠作用机制研究

摘要 目的：研究羌活地黄汤对佐剂性类风湿关节炎（RA）大鼠辅助性T细胞/调节性T细胞（Th17/Treg）失衡、血清基质金属蛋白酶-3（MMP-3）、基质金属蛋白酶-13（MMP-13）以及滑膜组织血管内皮生长因子（VEGF）、核因子-κB受体活化因子配基（RANKL） mRNA表达的影响。方法：取40只SD级大鼠进行研究，将其以随机数字表法分为正常对照组、模型组、羌活地黄汤组以及甲氨蝶呤组，每组各10只。除正常对照组外，其余各组大鼠均建立佐剂性RA动物模型。羌活地黄汤组予以羌活地黄汤灌胃干预，甲氨蝶呤组予以甲氨蝶呤灌胃干预，正常对照组及模型组均予以等量生理盐水灌胃干预。各组均进行为期28d的干预，比较各组体重、关节炎指数及关节肿胀度、外周血Th17/Treg相关指标、血清MMP-3、MMP-13水平、滑膜组织VEGF、RANKL mRNA表达。结果：模型组体重低于正常对照组，羌活地黄汤组、甲氨蝶呤组关节炎指数及关节肿胀度均低于模型组，而体重高于模型组（均P＜0.05）。模型组、羌活地黄汤组、甲氨蝶呤组的外周血CD4+IL-17+T、Th17/Treg均高于正常对照组，而Foxp3+CD4+CD25+Treg低于正常对照组，且羌活地黄汤组、甲氨蝶呤组的外周血CD4+IL-17+T、Th17/Treg均低于模型组，而Foxp3+CD4+CD25+Treg高于模型组（均P＜0.05）。模型组、羌活地黄汤组、甲氨蝶呤组的血清MMP-3、MMP-13水平均高于正常对照组，而羌活地黄汤组、甲氨蝶呤组的血清MMP-3、MMP-13水平均低于模型组（均P＜0.05）。模型组、羌活地黄汤组、甲氨蝶呤组的滑膜组织VEGF、RANKL mRNA表达水平均高于正常对照组，而羌活地黄汤组、甲氨蝶呤组的滑膜组织VEGF、RANKL mRNA表达水平均低于模型组（均P＜0.05）。结论：羌活地黄汤可改善佐剂性RA大鼠的症状以及Th17/Treg失衡状态，且有效改善其血清MMP-3、MMP-13水平以及滑膜组织VEGF、RANKL mRNA表达。     

川陈皮素对脑梗死缺血再灌注大鼠的保护作用及其机制研究

摘要 目的：研究川陈皮素对脑梗死缺血再灌注大鼠的保护作用及其机制。方法：将90只雄性Wistar大鼠随机分为空白对照组、假手术组、模型组及低剂量组、中剂量组及高剂量组,每组15只。空白对照组不予以任何处理,模型组、低剂量组、中剂量组及高剂量组其余各组大鼠均采用Long线栓法构建脑梗死缺血再灌注模型,假手术组除了不插入拴线,其他操作和模型组相同。造模后,空白对照组、假手术组及模型组分别予以10 mL/（kg?d）的生理盐水灌胃,低剂量组、中剂量组、高剂量组分别予以10 mL/（kg?d）、15 mL/（kg?d）、20 mL/（kg?d）川陈皮素灌胃。检测各组大鼠梗死面积以及神经细胞凋亡率,缺氧诱导因子-1α（HIF-1α）、血管内皮生长因子（VEGF）水平,炎症细胞因子水平,B淋巴细胞瘤-2（Bcl-2）,Bcl-2相关X蛋白（Bax）,半胱氨酸天冬氨酸蛋白酶-3（caspase-3）表达情况。结果：模型组、低剂量组、中剂量组、高剂量组梗死面积、神经细胞凋亡率以及HIF-1α、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-β）、Bax mRNA、caspase-3 mRNA水平均高于空白对照组及假手术组;且低剂量组、中剂量组、高剂量组较模型组低;降低呈剂量依赖性（均P＜0.05）。模型组、低剂量组、中剂量组、高剂量组VEGF、Bcl-2 mRNA水平均低于空白对照组及假手术组;且低剂量组、中剂量组、高剂量组较模型组高;降低呈剂量依赖性（均P＜0.05）。假手术组梗死面积以及神经细胞凋亡率均高于空白对照组（均P＜0.05）。结论：川陈皮素对脑梗死缺血再灌注大鼠的保护作用明显,其主要机制可能与调控HIF-1α、VEGF、炎症细胞因子以及凋亡相关基因表达有关。     

益肾化瘀汤对糖尿病肾病大鼠肾功能及外周血腺苷脱氨酶表达的影响

摘要 目的：研究益肾化瘀汤对糖尿病肾病（diabetic kidney disease, DKD）大鼠肾功能及外周血腺苷脱氨酶（adenosine deaminase, ADA）表达的影响。方法：将30只大鼠随机分为空白组、模型组和治疗组,每组10只。模型组和治疗组均建立DKD模型,治疗组给予益肾化瘀汤治疗30 d。分别于给药后的第1 d、第10 d、第20 d和第30 d检测各组大鼠的血糖水平、肾功能指标和血清ADA的表达水平,HE染色观察肾组织病理学变化。结果：模型组大鼠出现多饮多尿体重减轻的糖尿病症状,治疗组在给予益肾化瘀汤后上述症状均有所好转。模型组和治疗组的空腹血糖值（fasting blood glucose,FBG）水平均显著高于空白组（P＜0.05）,自第10 d开始治疗组大鼠FBG水平显著低于模型组（P＜0.05）。模型组和治疗组大鼠血清肌酐（serum creatinine, SCr）和血尿素氮（blood urea nitrogen, BUN）的表达水平显著高于空白组（P＜0.05）,自第10 d开始治疗组大鼠的Scr和BUN显著低于模型组（P＜0.05）。模型组和治疗组大鼠血清ADA的表达水平显著高于空白组（P＜0.05）,自第10 d开始治疗组大鼠ADA的表达显著低于模型组（P＜0.05）。结论：益肾化瘀汤可显著改善DKD大鼠的血糖水平、肾功能及血清ADA表达水平,具有一定的临床应用价值。     

小檗碱对幽门螺旋杆菌感染小鼠胃粘膜损伤和免疫功能的影响机制研究

摘要 目的：探讨小檗碱对幽门螺旋杆菌感染小鼠胃粘膜损伤和免疫功能的影响机制。方法：选择SPF雄性小鼠50只,随机分为5组,包括空白对照组、幽门螺杆菌模型组、小檗碱低剂量组（25 mg/mL,A组）、中剂量组（50 mg/mL,B组）和高剂量组（100 mg/kg/d,C组）。空白组大鼠腹腔注射等容量的生理盐水,其余组使用口服幽门螺杆菌的方法建立幽门螺旋杆菌感染小鼠模型。进行胃黏膜上皮细胞存活率和凋亡率检测,同时测定胃黏膜上皮细胞凋亡蛋白水平、炎症因子水平、免疫功能以及IL-4/STAT6 mRNA水平。结果：模型组、小檗碱低剂量组、中剂量组和高剂量组胃黏膜上皮细胞存活率均显著低于空白对照组（P<0.05）;且随着小檗碱剂量的增加,细胞存活率逐渐升高（P<0.05）;模型组、小檗碱低剂量组、中剂量组和高剂量组胃黏膜上皮细胞凋亡率均显著高于空白对照组（P<0.05）;且随着小檗碱剂量的增加,细胞凋亡率逐渐降低（P<0.05）;与模型组比较,小檗碱低、中、高剂量组小鼠胃黏膜上皮细胞凋亡蛋白Bax和Cl-caspase-3的水平、TNF-α、IFN-γ、IL-10和TGF-β的水平均显著降低（P<0.05）,且随着小檗碱剂量的增加,Bax和Cl-caspase-3的水平、TNF-α、IFN-γ、IL-10和TGF-β的水平逐渐降低（P<0.05）;与模型组比较,小檗碱低、中、高剂量组上清液中CD3⁺、CD4⁺和CD8⁺的水平、IL-4 mRNA和STAT6 mRNA均显著升高（P<0.05）,且随着小檗碱剂量的增加,CD3⁺、CD4⁺和CD8⁺水平、IL-4 mRNA和STAT6 mRNA逐渐升高（P<0.05）。结论：小檗碱能够减轻幽门螺旋杆菌感染小鼠胃粘膜损伤,提升免疫功能,可能与IL-4/STAT6信号通路有关。     

骨髓间充质干细胞移植对急性肝功能衰竭大鼠肝再生、炎症反应及转换生长因子-β受体的影响

摘要 目的：探讨骨髓间充质干细胞（BMSCs）移植对急性肝功能衰竭（ALF）大鼠肝再生、炎症反应及转换生长因子-β受体（TGF-βR）的影响。方法：将90只SD级大鼠以随机数表法分成模型组（n=30）、健康组（n=30）及治疗组（n=30）。健康组不予以任何处理,模型组和治疗组大鼠则通过四氯化碳蓖麻油溶液腹腔注射制作ALF大鼠模型,治疗组大鼠取BMSCs通过门静脉注射治疗,模型组则予以等量生理盐水干预。造模后第7 d,比较三组大鼠的肝功能指标水平,炎症反应以及TGF-βR相关指标表达情况,并进行相关性分析。结果：模型组与治疗组大鼠血清谷丙转氨酶（ALT）、谷草转氨酶（AST）以及总胆红素（TBIL）水平均高于健康组,但治疗组大鼠上述肝功能指标水平低于模型组（均P＜0.05）。模型组与治疗组大鼠血清肿瘤坏死因子-α（TNF-α）水平以及肝组织TNF-α mRNA表达均高于健康组,但治疗组大鼠血清TNF-α水平以及肝组织TNF-α mRNA表达低于模型组（均P＜0.05）。模型组与治疗组大鼠TGF-βR1和TGF-βR2蛋白表达均高于健康组,但治疗组大鼠上述蛋白表达低于模型组（均P＜0.05）。经Spearman相关性分析发现：ALT、AST及TBIL水平与血清TNF-α、TNF-α mRNA及TGF-βR1、TGF-βR2蛋白表达水平均呈正相关关系（均P＜0.05）。结论：BMSCs移植在促进ALF大鼠肝再生方面效果显著,且有效减轻炎症反应、下调TGF-βR1和TGF-βR2表达水平。     

三七总皂苷联合顺铂对胃癌大鼠肾损伤的改善作用及机制分析

摘要 目的：探讨三七总皂苷联合顺铂对胃癌大鼠肾损伤的改善作用并分析潜在机制。方法：选择60只健康SD雄性大鼠分为对照组、胃癌模型组、顺铂组及三七总皂苷组,各15只。除对照组外,其余组大鼠采用皮下接种胃癌BGC823细胞悬液法建立胃癌模型。建模成功后,给予对照组和胃癌模型组大鼠生理盐水腹腔注射和灌胃,给予顺铂组大鼠腹腔注射25 mg/kg顺铂注射液并灌胃生理盐水,给予三七总皂苷组大鼠腹腔注射25 mg/kg顺铂注射液并灌胃30 mg/kg三七总皂苷。分别于建模成功时、药物处理28 d时采用酶联免疫吸附法检测血清肌酐（SCr）、尿素氮（BUN）和尿液β-N-乙酰氨基葡萄糖苷酶（NAG）、肾损伤分子1（KIM-1）水平。处死大鼠后取肾脏,分别测定肾脏组织匀浆中超氧化物歧化酶（SOD）、丙二醛（MDA）、过氧化氢酶（CAT）、谷胱甘肽（GSH）水平,制备肾脏组织石蜡切片并行苏木精-伊红染色后观察大鼠肾组织的病理学变化。采用TUNEL染色法检测肾脏组织细胞凋亡情况,采用Western Blotting法检测肾脏组织中LC3、HIF-1α和Beclin1 蛋白表达情况。结果：顺铂组和三七总皂苷组大鼠血清SCr、BUN和尿液NAG、KIM-1水平均显著高于对照组和模型组（P<0.05）,三七总皂苷组大鼠血清SCr、BUN和尿液NAG、KIM-1水平显著高于顺铂组（P<0.05）。三七总皂苷组大鼠肾脏组织SOD、GSH水平显著低于模型组但显著高于顺铂组,MDA显著高于模型组但显著低于顺铂组（P＜0.05）,CAT与模型组无显著差异（P＜0.05）,但显著高于顺铂组（P>0.05）。顺铂组大鼠肾小管明显扩张、管腔狭窄,基底层上皮细胞水肿、坏死并形成空泡,肾小管。三七总皂苷组大鼠肾脏病理学改变程度显著轻于顺铂组。顺铂组和三七总皂苷组大鼠肾脏组织细胞凋亡指数显著增加,三七总皂苷组大鼠肾脏组织细胞凋亡指数显著低于顺铂组（P＜0.05）。顺铂组大鼠肾脏组织中LC3、HIF-1α和Beclin1蛋白水平均显著高于模型组,但显著低于三七总皂苷组（P＜0.05）。结论：三七总皂苷可能通过减轻过氧自由基和过氧化水平、增强线粒体自噬水平减少肾组织细胞凋亡,减轻顺铂引起的胃癌大鼠肾损伤。     

miR-152-3p调控Notch1/DLL4通路对家兔深II度烧伤创面血管生成的影响

摘要 目的：探究微小核糖核酸（miR）-152-3p调控果蝇Notch同源物1（Notch1）/Delta样配体4（DLL4）通路对家兔深II度烧伤创面血管生成的影响。方法：将50只新西兰家兔随机分为对照组、模型组、miR-152-3p拮抗剂（antagomir）组、miR-152-3p antagomir阴性对照+空载组、miR-152-3p antagomir+Notch1敲低组,每组10只,除对照组外其余各组家兔构建深II度烧伤模型,分组给药处理后,实时荧光定量聚合酶链式反应（qRT-PCR）检测各组家兔创面组织miR-152-3p与Notch1、DLL4 mRNA表达;检测各组家兔创面愈合率及微循环血流灌注值（MPD）;免疫组织化学染色检测各组家兔创面微血管密度（MVD）;酶联免疫吸附反应（ELISA）检测各组家兔血清血管内皮细胞生长因子（VEGF）及促血管生成素1（Ang1）水平;免疫印迹检测各组家兔创面组织VEGF、Ang1与Notch1/DLL4通路蛋白表达;双荧光素酶报告基因实验检测兔脐静脉内皮细胞中miR-152-3p对Notch1及DLL4的靶向调节。结果：与对照组相比,模型组家兔创面组织miR-152-3p与Notch1、DLL4 mRNA表达升高（P<0.05）,创面MPD及MVD、血清VEGF及Ang1水平、创面组织VEGF与Ang1蛋白表达降低（P<0.05）。与模型组相比,miR-152-3p antagomir组家兔创面组织miR-152-3p mRNA表达降低（P<0.05）,创面愈合率、创面MPD及MVD、血清VEGF及Ang1水平、创面组织Notch1、DLL4 mRNA及蛋白表达、创面组织VEGF与Ang1蛋白表达升高（P<0.05）;miR-152-3p antagomir阴性对照+空载组家兔各指标无明显差异（P＞0.05）;与miR-152-3p antagomir组相比,miR-152-3p antagomir+Notch1敲低组家兔创面组织miR-152-3p mRNA表达无明显差异（P＞0.05）,创面愈合率、创面MPD及MVD、血清VEGF及Ang1水平、创面组织Notch1、DLL4 mRNA及蛋白表达、创面组织VEGF与Ang1蛋白表达降低（P<0.05）。miR-152-3p可靶向下调兔脐静脉内皮细胞中Notch1及DLL4的表达。结论：敲低miR-152-3p可通过上调Notch1/DLL4通路而增强家兔深II度烧伤创面血管生成,进而促进其创面愈合。     

ATP/ADP exchange activity of gastric (H+ + K+)-ATPase

The ATP/ADP exchange is shown to be a partial reaction of the $\text{(}\text{H}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ by the absence of measurable nucleoside diphosphokinase activity and the insensitivity of the reaction to $\text{P}{}^1$, $\text{P}{}^5$ -di(adenosine-5′) pentaphosphate, a myokinase inhibitor. The exchange demonstrates an absolute requirement for Mg²⁺ and is optimal at an ADP/ATP ratio of 2. The high ATP concentration ($\text{K}{}_{0.5}\text{= 116 μ}\text{M}$) required for maximal exchange is interpreted as evidence for the involvement of a low affinity form of nucleotide site. The ATP/ADP exchange is regarded as evidence for an ADP-sensitive form of the phosphoenzyme. In native enzyme, pre-steady state kinetics show that the formation of the phosphoenzyme is partially sensitive to ADP while modification of the enzyme by pretreatment with 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) in the absence of Mg²⁺ results in a steady-state phosphoenzyme population, a component of which is ADP sensitive. The ATP/ADP exchange reaction can be either stimulated or inhibited by the presence of K⁺ as a function of pH and Mg²⁺.     

AutoFACT: AnAutomaticFunctionalAnnotation andClassificationTool

Background  

Assignment of function to new molecular sequence data is an essential step in genomics projects. The usual process involves similarity searches of a given sequence against one or more databases, an arduous process for large datasets.     

Ligand-dependent reactivity of (Na+ + K+)-ATPase with showdomycin

Showdomycin inhibited pig brain ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ with pseudo first-order kinetics. The rate of inhibition by showdomycin was examined in the presence of 16 combinations of four ligands, i.e., Na⁺, K⁺, Mg²⁺ and ATP, and was found to depend on the ligands added. Combinations of ligands were divided into five groups in terms of the magnitude of the rate constant; in the order of decreasing rate constants these were: (1)$\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$, (2) $\text{Mg}{}^{\mathrm{2+}}$, $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}$ and none, (3) $\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{,}\text{Na}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}$ and $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}$, (4) $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}\text{,}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}$ and $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}\text{, (5)}\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$ and ATP. The highest rate was obtained in the presence of Na⁺, Mg²⁺ and ATP. The apparent concentrations of Na⁺, Mg²⁺ and ATP for half-maximum stimulation of inhibition ($\text{K}{}_{0.5}{}^{\mathrm{<mtext>s</mtext>}}$) were 3 mM, 0.13 mM and 4μM, respectively. The rate was unchanged upon further increase in Na⁺ concentration from 140 to 1000 mM. The rates of inhibition could be explained on the basis of the enzyme forms present, including E₁, E₂, ES, E₁-P and E₂-P, i.e., E₂ has higher reactivity with showdomycin than E₁, while E₂-P has almost the same reactivity as E₁-P. We conclude that the reaction of ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ proceeds via at least four kinds of enzyme form (E₁, E₂, E₁ · nucleotide and EP), which all have different conformations.     

Characterization of cytochrome P-450SCC-containing liposomes

Purified cytochrome $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ from bovine adrenocortical mitochondria was incorporated into liposomes by the cholate-dilution method utilizing either dialysis or Sephadex gel filtration. Among synthetic phospholipids tested, dioleoylglycerophosphocholine showed the best stability during the incorporation of $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ into liposomes. A maximum amount of heme was incorporated into liposomes at a molar ratio of phospholipid to the cytochrome of approx. 200. When $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was incorporated into the dioleoylglycerophosphocholine liposomes by the cholate-filtration method, the $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}\text{-}\text{containing liposomes}$ showed two major populations on the elution pattern of the Sepharose 4B gel filtration, and were seen at a diameter of 200–600 Å and its aggregated forms. When the cytochrome was incorporated into dioleoylglycerophosphocholine liposomes or cholesterol-free adrenocortical mitochondrial liposomes, $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was less stable than $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ in aqueous solution. Cholesterol or adrenodoxin markedly stabilized the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. Liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ required cholesterol for its optimum reduction with adrenodoxin, adrenodoxin reductase, and NADPH in the presence of CO. About 70% of the total heme in the dioleoylglycerophosphocholine liposomes was reduced by the enzymatic reduction in the presence of cholesterol, indicating that 70% of the total molecules are exposed to the surface of the outer monolayer. In order to see the location of the heme in membrane, the dioleoylglycerophosphocholine-liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was subjected to $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ treatment. This reagent destroyed the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. These results suggest that the heme is located in the proximity of the $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ reacting sites which are exposed to the surface, or located on the vincinity of polar heads of the membrane.     

A/California/7/2009与A/California/4/2009病毒感染力比较

目的甲型H1N1流感病毒A/California/7/2009与A/California/4/2009病毒序列比较同源性在99%以上,本实验旨在比较两株病毒感染BALB/c小鼠研究感染力强弱。方法分别将A/California/7/2009（CA7）与A/California/4/2009（CA4）两株病毒分别连续10倍稀释后,对4~6周龄雌性BALB/c小鼠经乙醚麻醉后进行滴鼻攻毒,每个稀释度接种10只实验小鼠,测定CA7 MLD50为101.24/0.05 mL,检测小鼠感染、致病的多项指标,观察期为14 d。结果相同TCID50的CA7和CA4病毒感染小鼠,CA4感染小鼠后14 d内死亡率为20%,而CA7感染小鼠后8 d内死亡率为100%。CA7 106TCID50感染的小鼠病理表现为重度弥漫性间质性肺炎,CA4 106TCID50感染的小鼠病理表现为中度-重度间质性肺炎。结论在相同条件下,CA7感染力明显强于CA4。     

Characterization of partially purified (Na+ + K+)-ATPase from porcine lens

The partial purification of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ from pig lens has been achieved by treatment with deoxycholate followed by density gradient centrifugation. The specific activity of the final preparation, ranging from 300 to 500 nmol/h per mg protein, is increased approx. 100-fold compared to the homogenate. A parallel increase in $\text{p-}\text{nitrophenylphosphatase}$ activity is also observed. Sodium dodecyl sulfate (SDS) gel electrophoresis reveals six major protein bands, one of which is the 93 kDa α subunit of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ which can be phosphorylated by reaction with [γ-³²P]ATP. A second band contains a glycoprotein which displays an apparent molecular weight of 51 000 and thus appears to be the β subunit of the enzyme. The enzyme is sensitive to ouabain with the $\text{I}{}_{50}$ for $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ and $\text{p-}\text{nitrophenylphosphatase}$ inhibition being 1.2 and 1.3 μM, respectively. Several agents which inhibit $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ from other tissues such as oligomycin, Ca²⁺, vanadate, $\text{N-}\text{ethylmaleimide}$, $\text{p-}\text{chloromercuribenzenesulfonic acid}$ (PCMBS) and 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) also inhibit the lens enzyme. Monovalent cations other than K⁺ are partially effective in activating the ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}$)-ATPase and $\text{p-}\text{nitrophenylphosphatase}$ activities. The K⁺ congeners were relatively more effective in supporting $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ compared to $\text{p-}\text{nitrophenylphosphatase}$ activity. Other kinetic properties of the lens enzyme are also comparable to those of the enzyme from other tissues. Utilizing the partially purified membrane bound enzyme, discontinuities in Arrhenius plots of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ activity, $\text{p-}\text{nitrophenylphosphatase}$ activity and fluoresence polarization of the fluidity probe, 1,6-diphenyl-1,3,5-hexatriene (DPH), are observed near the physiological temperature of lens. The possible significance of these observations for the mechanism of cataract formation are discussed.     

An electron spin probe study of (Na+ + K+)-ATPase-Containing membranes

The modulating effect of membrane lipids on enzyme function has been described by several investigators. We have used the spin probe $\text{N-}\text{oxyl}\text{-4′,4′-}\text{dimethyloxazolidine}\text{-12-}\text{keto}$ methyl stearate (M 12-NSE) to study this interaction in ox brain membranes enriched with $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$. This methyl ester of stearic acid is practically insoluble in aqueous media, and consequently spectra of M 12-NSE-labelled preparations are free of “liquid lines”.At least two types of spectra may be obtained when ox brain microsomes are spin labelled with M 12-NSE, indicating the presence of two distinct binding sites. At one site the spin label is relatively unrestricted and gives rise to an isotropic spectrum. A second spectrum, which is obtained from spin label at another site, is similar to that which is observed after incorporation of M 12-NSE into phospholipid bilayers. This suggests that this latter site is within the core of the microsomal membrane.The two binding sites differ in their affinity for the spin probe. The low affinity site is both more abundant in crude preparations and is more easily removed by detergent treatment; spin labels at this site produce isotropic spectra. The high affinity sites are fewer in number and produce broad spectra. In addition these high affinity sites increase in concentration as the enzyme undergoes purification.The two sites are quite distinct in their sensitivity to ascorbic acid, the low affinity site showing a considerably greater rate of reduction by this agent.This study also demonstrates that the delipidation effects of sodium dodecyl sulfate and sodium deoxycholate on $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase-enriched}$ microsomes from ox brain are not identical.It is suggested that the two spin probe binding sites represent two different lipid domains, one of which is very closely associated with the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ enzyme and may reflect a protein-directed phospholipid specificity for this enzyme.     

Annular and non-annular binding sites on the (Ca2+ + Mg2+)-ATPase

Quenching of the fluorescence of the $\text{(}\text{Ca}{}^{\mathrm{2+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{)-}\text{ATPase}$ purified from muscle sarcoplasmic reticulum can be used to measure relative binding constants of hydrophobic compounds to the phospholipid-protein interface. We show that the binding constant for cholesterol is considerably less than that for phosphatidylcholine, so that cholesterol is effectively excluded from the phospholipid annulus around the ATPase. However, dibromocholestan-3β-ol causes quenching of the fluorescence of the ATPase, and so has access to other, non-annular sites. We suggest that these non-annular sites could be at protein/protein interfaces in ATPase oligomers. Oleic acid can bind at the phospholipid/protein interface, although its binding constant is less than that for a phosphatidylcholine, and it can also bind at the postulated non-annular sites. The effects of these compounds on the activity of the ATPase depend on the structure of the phospholipid present in the systems.     

Comparison of parameters estimated from A/Ci and A/Cc curve analysis

The parameters estimated from traditional A/C _i curve analysis are dependent upon some underlying assumptions that substomatal CO₂ concentration (C _i) equals the chloroplast CO₂ concentration (C _c) and the C _i value at which the A/C _i curve switches between Rubisco- and electron transport-limited portions of the curve (C _i-t) is set to a constant. However, the assumptions reduced the accuracy of parameter estimation significantly without taking the influence of C _i-t value and mesophyll conductance (g _m) on parameters into account. Based on the analysis of Larix gmelinii’s A/C _i curves, it showed the C _i-t value varied significantly, ranging from 24 Pa to 72 Pa and averaging 38 Pa. t-test demonstrated there were significant differences in parameters respectively estimated from A/C _i and A/C _c curve analysis (p<0.01). Compared with the maximum ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (V_cmax), the maximum electron transport rate (J_max) and J_max/V_cmax estimated from A/C _c curve analysis which considers the effects of g _m limit and simultaneously fits parameters with the whole A/C _c curve, mean V_cmax estimated from A/C _i curve analysis (V_cmax-C _i) was underestimated by 37.49%; mean Jmax estimated from A/C _i curve analysis (J_max-C _i) was overestimated by 17.8% and (J_max-C _i)/(V_cmax-C _i) was overestimated by 24.2%. However, there was a significant linear relationship between V_cmax estimated from A/C _i curve analysis and V_cmax estimated from A/C _c curve analysis, so was it J_max (p<0.05).     

Regulation of rat brain (Na+ + K+)-ATPase activity by cyclic AMP

The interaction between the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ and the adenylate cyclase enzyme systems was examined. Cyclic AMP, but not 5′-AMP, cyclic GMP or 5′-GMP, could inhibit the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ enzyme present in crude rat brain plasma membranes. On the other hand, the cyclic AMP inhibition could not be observed with purified preparations of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ enzyme. Rat brain synaptosomal membranes were prepared and treated with either NaCl or cyclic AMP plus NaCl as described by Corbin, J., Sugden, P., Lincoln, T. and Keely, S. ((1977) J. Biol. Chem. 252, 3854–3861). This resulted in the dissociation and removal of the catalytic subunit of a membrane-bound cyclic AMP-dependent protein kinase. The decrease in cyclic AMP-dependent protein kinase activity was accompanied by an increase in $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ activity. Exposure of synaptosomal membranes containing the cyclic AMP-dependent protein kinase holoenzyme to a specific cyclic AMP-dependent protein kinase inhibitor resulted in an increase in $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ enzyme activity. Synaptosomal membranes lacking the catalytic subunit of the cyclic-AMP-dependent protein kinase did not show this effect. Reconstitution of the solubilized membrane-bound cyclic AMP-dependent protein kinase, in the presence of a neuronal membrane substrate protein for the activated protein kinase, with a purified preparation of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$, resulted in a decrease in overall $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ activity in the presence of cyclic AMP. Reconstitution of the protein kinase alone or the substrate protein alone, with the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ has no effect on $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ activity in the absence or presence of cyclic AMP. Preliminary experiments indicate that, when the activated protein kinase and the substrate protein were reconstituted with the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ enzyme, there appeared to be a decrease in the Na⁺-dependent phosphorylation of the Na⁺-ATPase enzyme, while the K⁺-dependent dephosphorylation of the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ was unaffected.