注射用益气复脉（冻干）对心力衰竭感染性休克大鼠的药效研究

目的 探讨注射用益气复脉（冻干）（YQFM）对心力衰竭感染性休克大鼠的药效作用。方法 通过结扎冠状动脉左前降支以及尾静脉推注脂多糖（LPS，25 mg·kg^-1）的方法建立心力衰竭感染性休克大鼠模型，随机将造模后大鼠分为模型组，肾上腺素（10 μg·kg^-1）组，YQFM低、高剂量（232.2、464.3 mg·kg^-1）组，联合给药（肾上腺素10 μg·kg^-1＋YQFM 464.3 mg·kg^-1）组，假手术组进行同样操作但不结扎不推注LPS。造模后即给药，尾iv给药1次，模型组和假手术组大鼠给予等体积的0.9%氯化钠注射液。使用八通道无创血压仪检测造模前、造模后及给药后大鼠收缩压变化；ELISA法检测各组大鼠血清中脑钠肽（BNP）、氨基端前心钠肽（NT-proANP）、肌酸激酶同工酶（CK-MB）、乳酸脱氢酶（LDH）、丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）和超氧化物歧化酶（SOD）水平。结果 各组大鼠的基础收缩压无显著性差异，与假手术组比较，造模各组大鼠收缩压显著降低（P＜0.001）；与模型组比较，各给药组大鼠收缩压显著回升（P＜0.05、0.001）。与假手术组相比，模型组血清NT-proANP、BNP、CK-MB、LDH、ALT、AST水平显著升高（P＜0.001），SOD水平显著降低（P＜0.001）；与模型组相比，肾上腺素组，YQFM 232.2、464.3 mg·kg^-1组和联合给药组的NT-proANP、BNP、CK-MB、LDH、ALT、AST水平均显著下降（P＜0.05、0.01、0.001），肾上腺素组、YQFM 464.3 mg·kg^-1组和联合给药组SOD水平显著升高（P＜0.05、0.01、0.001）。结论 YQFM可以显著回升心力衰竭感染性休克大鼠的收缩压水平，改善血清中相关生化指标水平，并且与肾上腺素联合应用效果最好。     

注射用益气复脉（冻干）不同给药途径对心力衰竭大鼠的药效作用对比研究

目的 探讨注射用益气复脉（冻干）（YQFM）不同给药途径对心力衰竭大鼠的药效。方法 将70只经腹主动脉结扎造成心力衰竭模型的SD大鼠随机分为7组：模型组（ig＋尾iv 0.9%氯化钠注射液），YQFM尾iv低、高剂量组（ig 0.9%氯化钠注射液＋尾iv YQFM 464.3、928.6 mg·kg^-1，低剂量为临床等效剂量），益气复脉胶囊组（ig益气复脉胶囊246.3 mg·kg^-1＋尾iv 0.9%氯化钠注射液），YQFM ig组（ig YQFM 464.3 mg·kg^-1＋尾iv 0.9%氯化钠注射液），卡托普利片组（ig卡托普利片3.35 mg·kg^-1＋尾iv 0.9%氯化钠注射液），联合给药组（ig卡托普利片3.35 mg·kg^-1＋尾iv YQFM 464.3 mg·kg^-1），另取10只进行切口不进行结扎SD大鼠为假手术组（ig＋尾iv 0.9%氯化钠注射液）。分别于给药后1 h的第1、3、5、7、14天眼内眦取血，酶联免疫吸附试验（ELISA）法检测大鼠血清中心钠肽（ANP）、脑钠肽（BNP）、内皮素（ET）水平；连续给药14 d，给药结束后对各组大鼠进行心脏超声检测；取出心脏，HE染色后观察病理变化。结果 与模型组相比，给药后1 d，YQFM尾iv低、高剂量组及卡托普利片组和联合给药组血清ANP水平显著降低（P＜0.05、0.01），YQFM尾iv低、高剂量组和联合给药组血清BNP、ET水平显著降低（P＜ 0.05）；给药后7、14 d，各给药组血清ANP、BNP、ET水平显著降低（P＜0.05、0.001）；各给药组的左室短轴缩短率（LVFS）、左室射血分数（LVEF）、E峰与A峰的比值（E/A）均显著上升（P＜0.001）；各给药组心肌细胞病理变化有明显好转。与YQFM ig组相比，给药后1 d YQFM尾iv低、高剂量组和给药后14 dYQFM尾iv低剂量组血清ANP水平显著降低（P＜0.05）；给药后1、7 d YQFM尾iv低、高剂量组和给药后14 d YQFM尾iv低剂量组血清BNP水平显著降低（P＜0.05、0.01、0.001）；给药1 d YQFM尾iv低、高剂量组和给药7、14 d YQFM尾iv低剂量组血清ET水平显著降低（P＜0.05、0.001）； YQFM尾iv低、高剂量组的E/A均显著升高（P＜0.05、0.001）。结论 不同给药途径的YQFM均可以对心力衰竭大鼠发挥治疗作用，尾iv途径比ig途径治疗效果更好，也能更早发挥药效。     

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。     

丹酚酸B镁对兔急性心梗再灌注后无复流心肌损伤的保护作用

目的 评价丹酚酸B镁（salvianolic acid B,Sal-B）对兔急性心肌梗死再灌注后心肌损伤的保护作用。方法 新西兰大白兔40只随机分成4组,即假手术组、心肌缺血再灌注（myocardial ischemia/reperfusion,MI/R）、再灌注低剂量组（Sal-B20 mg·kg^-1组）、再灌注高剂量组（Sal-B 60 mg·kg^-1组）,每组10只。假手术组只开胸不结扎,其余3组结扎左室缘支90 min,切断结扎线120 min,建立MI/R模型。各组分别于结扎左心室缘支前5 min、结扎后90 min、再灌注120 min时取血,检测肌酸激酶同工酶（CK-MB）、心肌肌钙蛋白I （cTnI）,并评估缺血范围、无复流范围及梗死区心肌范围。结果 结扎90 min后,MI/R组、Sal-B 20 mg·kg^-1组和Sal-B 60 mg·kg^-1组3组之间CK-MB、cTnI水平差异无统计学意义。再灌注120 min后,Sal-B 60 mg·kg^-1组的血清CK-MB、cTnI水平显著低于MI/R组、Sal-B 20 mg·kg^-1组,差异有统计学意义（P<0.05）。各组染色所测的冠脉结扎区心肌缺血范围基本一致。与MI/R组、Sal-B 20 mg·kg^-1组比,Sal-B 60 mg·kg^-1组可以显著减少无复流面积（P<0.05）和梗死面积（P<0.05）,MI/R组和Sal-B 20 mg·kg^-1组之间差异无统计学意义。结论 Sal-B 60 mg·kg^-1能在一定程度上减轻心肌细胞结构损伤,缩小心肌梗死面积,减轻无复流的发生。     

丹参酮ⅡA通过PKC/Cx43通路减轻大鼠心肌缺血再灌注致心律失常

目的 探讨丹参酮Ⅱ_A(TA)对再灌注致心律失常的改善作用及机制。方法 取60只SD大鼠随机分为6组：对照组,模型组,TA低、高剂量(10、20 mg·kg^-1)组,蛋白激酶C(PKC)激活剂PMA(5 mg·kg^-1)组,TA(20 mg·kg^-1)联合PKC抑制剂Rottlerin(5 mg·kg^-1)组,每组10只。构建SD大鼠心肌缺血再灌注(I/R)模型,缺血30 min再灌注30 min;再灌注期间记录各组小鼠Ⅱ导联心电图并对再灌注后心律失常严重性进行评分;再灌注结束后,取颈静脉血采用试剂盒检测心肌损伤指标肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)、天冬氨酸转氨酶(AST)和心肌肌钙蛋白(cTnT)水平;取左心室心脏组织,使用试剂盒检测丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性,实时荧光定量PCR(qRT-PCR)法检测PKC、缝隙连接蛋白43(Cx43)mRNA表达,Western blotting法检测PKC、Cx43蛋白表达水平和磷酸化水平。结果 ...     

注射用丹参多酚酸对脑缺血再灌注大鼠脑损伤的保护作用

目的 考察注射用丹参多酚酸（SAFI）对脑缺血再灌注大鼠脑损伤的保护作用。方法 线拴法构建大脑中动脉缺血再灌注（MCAO/R）大鼠模型,将造模成功的大鼠随机分为模型组、丁苯酞氯化钠注射液（阳性药,9 mL·kg^-1）组和SAFI低、中、高剂量（5.85、11.71、23.42 mg·kg^-1,11.71 mg·kg^-1为临床等效剂量）组,每组12只。假手术组和模型组给予0.9%氯化钠注射液,SAFI每天给药1次,丁苯酞氯化钠注射液每天给药2次,尾iv连续给药14 d。给药期间称大鼠体质量;给药前后对各组大鼠进行神经功能评分;给药后采用TTC染色法检测脑梗死体积;酶联免疫吸附（ELISA）法检测血清中γ干扰素（IFN-γ）、白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）和超氧化物歧化酶（SOD）的水平;HE染色观察脑组织病理形态;尼氏染色观察海马区尼氏小体形态变化情况。结果 给药14 d后,与模型组比较,SAFI 5.85、11.71、23.42 mg · kg^-1组和丁苯酞氯化钠注射液组大鼠体质量显著增加（P ＜ 0.001）,脑组织梗死体积显著缩小（P＜0.001） ;SAFI 11.71、23.42 mg·kg^-1组和丁苯酞氯化钠注射液组神经功能评分显著降低（P＜0.05、0.01）,IFN-γ、IL-1β和TNF-α水平均显著降低（P＜0.01、0.001）,SOD水平显著升高（P＜0.01、0.001）; SAFI 23.42 mg·kg^-1组和丁苯酞氯化钠注射液组IL-6水平显著降低（P＜0.05、0.01）; SAFI可明显改善MCAO/R大鼠脑组织缺血半暗带区病理损伤,抑制尼氏小体数的减少。结论 SAFI对脑缺血再灌注大鼠脑损伤具有明显的保护作用。     

乳香没药精油自微乳的制备与抗炎镇痛作用评价

目的 制备乳香没药精油（FMO）自微乳化给药系统（FMO-SMEDDSs）,并评价其抗炎镇痛效果。方法 水蒸气蒸馏法提取FMO,考察FMO与不同种类油相、乳化剂和助乳化剂的配伍相容性并确定了FMO-SMEDDSs的处方组成,最终根据伪三元相图法得到其处方配比;以热力学稳定性、动态光散射、透射电镜等实验手段评价FMO-SMEDDSs的理化性质。将 SD 大鼠随机分为 5 组 ：对照组、模型组、布洛芬（阳性药 ,20 mg·kg^-1）组、FMO（生药剂量 90 mg·kg^-1）组、FMOSMEDDSs （90 mg·kg^-1）组,每天ig给药2次,连续给药7 d,对照组与模型组ig生理盐水;除对照组外,其余4组大鼠均在右后足跖sc 40.0%甲醛溶液0.1 mL,6 h后用千分尺测量大鼠右后足厚度,并计算肿胀度和肿胀抑制率;ELISA试剂盒法分别检测致炎足足底组织中前列腺素E₂（PGE₂）水平,血清白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）水平。通过小鼠扭体法评价布洛芬（40 mg·kg^-1）组、FMO（180 mg·kg^-1）组、FMO-SMEDDSs（180 mg·kg^-1）的镇痛效果。结果 根据配伍相容性及伪三元相图结果,分别选择肉豆蔻酸异丙酯（IPM）、聚山梨酯 80 和异丙醇作为 FMO-SMEDDSs 的油相、乳化剂和助乳化剂,配比为 4∶4∶2;FMO-SMEDDSs形成的微乳平均粒径为（57.8±1.1）nm,PDI为（0.216±0.014）,Zeta电位为（-11.5±0.05）mV,在透射电镜下可观察到微乳呈球状,FMO-SMEDDSs热力学稳定性良好。与模型组比较,布洛芬、FMO、FMOSMEDDSs组大鼠的致炎足肿胀度及肿胀率均显著降低（P＜0.05）,PGE₂、TNF-α和IL-6水平显著降低（P＜0.05）;与FMO组比较,FMO-SMEDDSs组大鼠致炎足肿胀度及肿胀率进一步显著降低（P＜0.05）,PGE₂、TNF-α和IL-6水平进一步显著降低（P＜0.05）。与模型组比较,ig布洛芬、FMO以及FMO-SMEDDSs后均能显著延长小鼠扭体反应潜伏期,显著减少15 min内的扭体次数（P＜0.05）;相对于FMO组,FMO-SMEDDSs抑制小鼠扭体反应作用更明显。结论 成功制备FMO-SMEDDSs,其具有良好的抗炎镇痛的作用。     

PKC-ERK1/2通路在臭氧预处理减轻大鼠肝缺血再灌注损伤的作用

目的 探讨PKC介导的ERK1/2信号通路在臭氧（ozone，O₃）预处理大鼠肝缺血再灌注中的作用。方法 60只大鼠随机分成6组：对照组、缺血再灌注组、O₃预处理组、O₃预处理+ERK抑制剂组（O₃+PD98059组）、O₃预处理+PKC抑制剂组（O₃+CHE组）、缺血再灌注+PKC激活剂组（IR+PMA组）。除对照组外，其余各组均进行肝缺血再灌注手术。O₃相关组予O₃预处理，调节剂组予相应的调节剂。分别检测各组的血清中丙氨酸氨基转移酶、天冬氨酸氨基转氨酶水平，进行病理学观察，Western blotting检测肝组织中的热休克蛋白70（heat shock protein 70，HSP70）、蛋白激酶C（protein kinase C，PKC）和细胞外调节蛋白激酶1/2（extracellular regulated protein kinases，ERK1/2）的表达水平。结果 与对照组相比，缺血再灌注组肝组织细胞损伤明显加重（P<0.05），肝组织中PKC、ERK1/2的磷酸化和HSP70的表达水平明显升高（P<0.05）。与缺血再灌注组相比，O₃相关组肝组织细胞损伤明显减轻（P<0.05），肝组织中PKC、ERK1/2的磷酸化和HSP70的表达水平明显升高（P<0.05）。与O₃预处理组相比，当使用PKC和ERK1/2抑制剂后，肝组织细胞损伤明显加重（P<0.05），肝组织中PKC、ERK1/2的磷酸化和HSP70的表达水平明显降低（P<0.05）。结论 O₃氧化预处理可通过激活PKC介导的ERK1/2信号通路，使HSP70的表达水平明显增加，使大鼠肝脏缺血再灌注损伤明显减轻。     

nNOS抑制剂亚胺基烯丁基-L-鸟氨酸对心肌缺血再灌注损伤的影响及机制

目的 探讨nNOS选择性抑制剂亚胺基烯丁基-L-鸟氨酸（L-VNIO）对心肌缺血再灌注（I/R）损伤的影响及机制。方法 构建SD大鼠离体心脏I/R模型和H9c2细胞缺氧/复氧（H/R）模型；nNOS抑制剂L-VNIO（10 μmol·L^-1）持续给药整个再灌注或复氧过程。TTC染色测定心肌梗死面积；流式细胞术检测H9c2细胞凋亡率；Fluo-3/AM Ca²⁺荧光探针通过流式细胞仪检测H9c2细胞内Ca²⁺浓度；试剂盒法测定离体心脏灌流液乳酸脱氢酶（LDH）、丙二醛（MDA）水平以及H9c2细胞MDA水平和超氧化物歧化酶（SOD）活性；离体心脏提取肌浆网，试剂盒法检测肌浆网Ca²⁺-ATP酶（SERCA）活性，Western blotting检测肌浆网SERCA蛋白表达；Western blotting检测离体心脏中受磷蛋白（PLB）和兰尼碱受体2（RyR2）蛋白表达水平和磷酸化水平。结果 与I/R或H/R模型组相比，L-VNIO显著降低细胞凋亡率，减少心肌梗死面积，降低LDH、MDA水平，提高SOD活性，差异均有统计学意义（P<0.05）；此外，与I/R或H/R模型组相比，L-VNIO组明显降低细胞内Ca²⁺超载，增高PLB磷酸化水平，降低RyR2磷酸化水平，增强SERCA活性（P<0.05）。结论 nNOS抑制剂L-VNIO可以减轻I/R损伤，机制与调节Ca²⁺转运相关蛋白而降低I/R引起的Ca²⁺超载相关。     

穿山龙复方水煎液对痛风性关节炎合并高尿酸血症诱导痛风性肾病大鼠肾脏的保护作用

目的 探讨穿山龙复方水煎液对痛风性关节炎（GA）合并高尿酸血症（HUA）诱导痛风性肾病（GN）大鼠肾脏的保护作用。方法 将48只雄性SD大鼠分为6组：对照组、模型组、秋水仙碱（阳性对照,0.03 mg·kg⁻¹）组及穿山龙复方水煎液高、中、低剂量（6.300、3.150、1.575 mg·kg⁻¹）组。各给药组连续7 d ig 10 mL·kg⁻¹相应药液;对照、模型组各ig生理盐水10 mL·kg⁻¹。给药过程中,除对照组外,其余建立GA合并HUA诱导的GN模型：每天2次ip 3%的氧嗪酸钾溶液（10 mL·kg⁻¹）,连续1周;在大鼠右侧踝关节后侧沿跟腱内侧以30°～40°方向插入至关节腔,将0.2 mL尿酸钠溶液（25 mg·mL⁻¹）注入到关节腔内,以关节囊对侧鼓起为注入标准,饲养过程中给予10%酵母饲料。称双侧肾脏质量,计算肾脏系数;HE染色后观察肾脏组织病理学变化;自动生化分析仪检测大鼠血尿酸（SUA）、血肌酐（SCr）、血清尿素氮（BUN）水平以及尿液尿酸（UUA）、尿肌酐（UCr）水平;试剂盒法检测血清中巨噬细胞趋化蛋白-1（MCP-1）、环氧合酶-2（COX-2）、β₂-微球蛋白（β₂-Mg）及尿液中β₂-Mg水平;以实时荧光定量PCR（qRT-PCR）法测定大鼠肾脏尿酸转运蛋白1（URAT1）、有机阴离子转运体1（OAT1）、有机阴离子转运体3（OAT3）、葡萄糖转运体9（GLUT9）、ABC转运蛋白G家族成员2（ABCG2）mRNA表达。结果 与模型组比较,穿山龙复方水煎液各剂量组和秋水仙碱组的肾脏系数显著降低（P＜0.01）,肾损伤明显减轻;穿山龙复方水煎液各剂量组及秋水仙碱组血清SUA、SCr、BUN、MCP-1、COX-2、β₂-Mg水平及尿液β₂-Mg水平显著降低（P＜0.05、0.01）,UUA和UCr水平显著升高（P＜0.05、0.01）;肾脏URAT1、GLUT9mRNA表达显著降低（P＜0.05、0.01）,OAT1、OAT3、ABCG2 mRNA表达显著升高（P＜0.05、0.01）。结论 穿山龙复方水煎液改善GN大鼠肾损伤,作用机制与抗炎,上调OAT1、OAT3、ABCG2 mRNA水平,促进UA排泄,下调URAT1、GLUT9 mRNA水平抑制UA重吸收相关。     

Natural phospholipase A2 myotoxin inhibitor proteins from snakes, mammals and plants

A renewed interest in the phenomenon of inter- and intra-species resistance towards the toxicity of snake venoms, coupled with the search for new strategies for treatment of snake envenomations, has prompted the discovery of proteins which neutralize the major toxic components of these venoms. Among these emerging groups of proteins are inhibitors of toxic phospholipases A₂ (PLA₂s), many of which exhibit a wide range of toxic effects including muscle-tissue damage, neurotoxicity, and inflammation. These proteins have been isolated from both venomous and non-venomous snakes, mammals, and most recently from medicinal plant extracts. The snake blood-derived inhibitors have been grouped into three major classes, α, β, and γ, based on common structural motifs found in other proteins with diverse physiological properties. In mammals, DM64, an anti-myotoxic protein isolated from opossum serum, belongs to the immunoglobulin super gene family and is homologous to human α₁B-glycoprotein and DM43, a metalloproteinase inhibitor from the same organism. In plants, a short note is made of WSG, a newly described anti-toxic-PLA₂ glycoprotein isolated from Withania somnifera (Ashwaganda), a medicinal plant whose aqueous extracts neutralize the PLA₂ activity of the Naja naja venom. The implications of these new groups of PLA₂ toxin inhibitors in the context of our current understanding of snake biology as well as in the development of novel therapeutic reagents in the treatment of snake envenomations worldwide are discussed.     

Histamine H4 receptor-RGS fusion proteins expressed in Sf9 insect cells: A sensitive and reliable approach for the functional characterization of histamine H4 receptor ligands

The human histamine H₄ receptor (hH₄R), co-expressed with Gα_i2 and Gβ₁γ₂ in Sf9 cells, is highly constitutively active. In the steady-state GTPase assay, the full agonist histamine (HA) induces only a relatively small signal (∼20-30%), resulting in a low signal-to background ratio. In order to improve this system for ligand screening purposes, the effects of the regulators of G-protein signaling (RGS) RGS4 and RGS19 (GAIP) were investigated. RGS4 and GAIP were fused to the C-terminus of hH₄R or co-expressed with non-fused hH₄R, always combined with Gα_i2 and Gβ₁γ₂. The non-fused RGS proteins did not significantly increase the relative effect of HA. With the hH₄R-RGS4 fusion protein the absolute GTPase activities, but not the relative HA-induced signal were increased. Fusion of hH₄R with GAIP caused a selective increase of the HA signal, resulting in an enhanced signal-to-noise ratio. A detailed characterization of the hH₄R-GAIP fusion protein (co-expressed with Gα_i2 and Gβ₁γ₂) and a comparison with the data obtained for the non-fused hH₄R (co-expressed with Gα_i2 and Gβ₁γ₂) led to the following results: (i) the relative agonist- and inverse agonist-induced signals at hH₄R-GAIP are markedly increased. (ii) Compared to the wild-type hH₄R, standard ligands show unaltered potencies and efficacies at hH₄R-GAIP. (iii) Like hH₄R, hH₄R-GAIP shows high and NaCl-resistant constitutive activity. (iv) hH₄R-GAIP shows the same G-protein selectivity profile as the non-fused hH₄R. Collectively, hH₄R-GAIP provides a sensitive test system for the characterization of hH₄R ligands and can replace the non-fused hH₄R in steady-state GTPase assays.     

Gene silencing efficiency of shRNA expression vectors targeting Cx43 in vitro

Our previous studies showed that there were close relationships between connexin 43 (Cx43) and acupoints and meridians. In order to further investigate the effect of Cx43 in acupuncture treatment, RNA interference technique was used to construct small hairpin RNA (shRNA) expression vectors targeting Cx43 and identify the efficiency of RNA interference in NIH/3T3 cell lines for further use in vivo. Aiming directly at the two targets of Cx43 mRNA sequence of the rat and mouse homology region, we synthesized two pairs of complementary oligonucleotide strands in vitro. Double strands were formed after annealing, and then inserted into Pgenesil-1 plasmid expression vector. After identification by enzyme cutting and sequencing, the recombinant plasmids named P-Cx43-shRNA (1), P-Cx43-shRNA (2) and P-con-shRNA were transfected into the NIH/3T3 cells. Immunofluorescence and Western blot assays were used to detect the protein level of Cx43 after being screened by G418. The results of enzyme cutting and sequencing showed that we successfully constructed two shRNA expression vectors targeting Cx43, and a control expression vector for rat and mouse. Also, the Cx43 protein level was decreased by 73.5% (P<0.01) and 10.8%, accordingly. The Cx43 protein level was not influenced by the transfection of P-con-shRNA. The outcomes demonstrate that the plasmid P-Cx43-shRNA (1) can specifically silence better the expression of Cx43 in NIH/3T3 cells, which offers an experimental evidence for further in vivo investigation.     

四苯硼钠滴定液浓度测量的不确定度评定

目的 对按中国药典2010年版第一增补本方法配制和标定的四苯硼钠滴定液(0.02 mol·L^-1)浓度进行不确定度评定。方法 通过对不确定度来源分析,建立测量模型,对标定过程中各不确定度的分量进行分析评估。结果 通过计算各变量的不确定度分量,得到本次标定浓度的相对标准不确定度为4.46×10^-3,合成标准不确定度为8.9×10^-5 mol·L^-1,扩展不确定度U=0.000 18 mol·L^-1,k=2。结论 建立了四苯硼钠滴定液浓度的测量不确定度评定方法,通过分析评估各分量不确定度的大小而明确测量不确定度的主要因素,优化实验条件使测定结果更加可靠准确。     

Regional divergence of phospholipase A2-like protein cDNAs between New Guinean and Australian Pseudechis australis

Snake Phospholipase A₂ (PLA₂) exhibits diverse pharmacological effects, such as hemolysis, myotoxicity, and neurotoxicity. In this study, we identified 10 novel PLA₂-like protein cDNAs, which we named Pr 1-10, from the venom gland cDNA library of Papuan pigmy mulga snake (New Guinean Pseudechis australis). The deduced amino acid sequence of Pr 1, which ortholog has not been reported in mulaga snake (Australian P. australis) yet, shows 78.8% identity with the ortholog in Australian tiger snake (Notechis scutatus scutatus). The amino acid sequences of Pr 2-10 are 92.4-99.3% identical with their orthologs and paralogs in Australian P. australis.     

The endocannabinoid 2-arachidonylglycerol is a negative allosteric modulator of the human A3 adenosine receptor

Studies of endogenous cannabinoid agonists, such as 2-arachidonylglycerol (2-AG), have revealed their potential to exert modulatory actions on other receptor systems in addition to their ability to activate cannabinoid receptors. This study investigated the effect of cannabinoid ligands on the human adenosine A₃ (hA₃R) receptor. The endocannabinoid 2-AG was able to inhibit agonist ([¹²⁵I]N⁶-(4-amino-3-iodobenzyl) adenosine-5′-(N-methyluronamide) - [¹²⁵I] AB MECA) binding at the hA₃R. This inhibition occurred over a narrow range of ligand concentration and was characterized by high Hill coefficients suggesting a non-competitive interaction. Furthermore, in the presence of 2-AG, the rate of [¹²⁵I] AB MECA dissociation was increased, consistent with an action as a negative allosteric modulator of the hA₃R. Moreover, by measuring intracellular cAMP levels, we demonstrate that 2-AG decreases both the potency of an agonist at the hA₃R and the basal signalling of this receptor. Since the hA₃R has been shown to be expressed in astrocytes and microglia, these findings may be particularly relevant in certain pathological states such as cerebral ischemia where levels of 2-AG and anandamide are raised.     

AKAP-dependent sensitization of Cav3.2 channels via the EP4 receptor/cAMP pathway mediates PGE2-induced mechanical hyperalgesia

Background and Purpose

The Ca_v3.2 isoform of T-type Ca²⁺ channels (T channels) is sensitized by hydrogen sulfide, a pro-nociceptive gasotransmitter, and also by PKA that mediates PGE₂-induced hyperalgesia. Here we examined and analysed Ca_v3.2 sensitization via the PGE₂/cAMP pathway in NG108-15 cells that express Ca_v3.2 and produce cAMP in response to PGE₂, and its impact on mechanical nociceptive processing in rats.

Experimental Approach

In NG108-15 cells and rat dorsal root ganglion (DRG) neurons, T-channel-dependent currents (T currents) were measured with the whole-cell patch-clamp technique. The molecular interaction of Ca_v3.2 with A-kinase anchoring protein 150 (AKAP150) and its phosphorylation were analysed by immunoprecipitation/immunoblotting in NG108-15 cells. Mechanical nociceptive threshold was determined by the paw pressure test in rats.

Key Results

In NG108-15 cells and/or rat DRG neurons, dibutyryl cAMP (db-cAMP) or PGE₂ increased T currents, an effect blocked by AKAP St-Ht31 inhibitor peptide (AKAPI) or KT5720, a PKA inhibitor. The effect of PGE₂ was abolished by RQ-00015986-00, an EP₄ receptor antagonist. AKAP150 was co-immunoprecipitated with Ca_v3.2, regardless of stimulation with db-cAMP, and Ca_v3.2 was phosphorylated by db-cAMP or PGE₂. In rats, intraplantar (i.pl.) administration of db-cAMP or PGE₂ caused mechanical hyperalgesia, an effect suppressed by AKAPI, two distinct T-channel blockers, NNC 55-0396 and ethosuximide, or ZnCl₂, known to inhibit Ca_v3.2 among T channels. Oral administration of RQ-00015986-00 suppressed the PGE₂-induced mechanical hyperalgesia.

Conclusion and Implications

Our findings suggest that PGE₂ causes AKAP-dependent phosphorylation and sensitization of Ca_v3.2 through the EP₄ receptor/cAMP/PKA pathway, leading to mechanical hyperalgesia in rats.     

The effects of CCK-4 on dopamine D1 agonist-induced grooming are blocked by a CCKA receptor antagonist: Evidence for a novel CCK receptor subtype?

The neuropeptide cholecystokinin (CCK) has been shown to interact with dopamine in various ways, including attenuation of dopamine D₁ receptor-mediated vacuous chewing and grooming. While we have demonstrated a clear role for the CCK_A receptor in the attenuation of dopamine D₁ agonist-induced vacuous chewing, studies of grooming yielded anomolous results. We examined the effects of selective CCK receptor antagonists on the attenuation of SKF 38393-induced grooming by the CCK_B agonist CCK-4. Administration of SKF 38393 (5 mg/kg s.c.) to male Sprague-Dawley rats resulted in a significant increase in grooming which was reduced to control levels by CCK-4 (20 mg/kg i.p.). Pretreatment with either the CCK_A receptor antagonist devazepide or the CCK_B receptor antagonist L-365,260 significantly attenuated this effect over a range of doses (20, 100, 500 μg/kg i.p.). The suppression of dopamine D₁ agonist-induced grooming by CCK-4 does not appear to reflect a non-specific effect of anxiogenesis, as it was unaffected by the anxiolytic diazepam. The CCK receptor antagonists alone were without behavioural effect. Taken together with previous studies in models of anxiety and analgesia, our findings lend further support to the hypothesis that CCK-4 may act at a novel receptor subtype.