In this study, we investigated the effects of a combination of Ginkgo biloba extracts （GBE） and phosphodiesterase type 5 （PDE-5） inhibitors on the muscular tone of the corpus cavernosum and potassium channel activ...In this study, we investigated the effects of a combination of Ginkgo biloba extracts （GBE） and phosphodiesterase type 5 （PDE-5） inhibitors on the muscular tone of the corpus cavernosum and potassium channel activity of corporal smooth muscle cells. Strips of corpus cavernosum from male New Zealand white rabbits were mounted in organ baths for isometric tension studies. After contraction with 1 × 10^-5 mol I^-1 norepinephrine, GBE （0.01-1 mg ml^-1） and mirodenafil （0.01-100 nmol I^-1） were added together into the organ bath. In electrophysiological studies, whole-cell currents were recorded by the conventional patch-clamp technique in cultured smooth muscle cells of the human corpus cavernosum. The corpus cavemosum was relaxed in response to GBE in a dose-dependent manner （from 0.64%±8.35% at 0.01 mg ml^-1 to 52.28%±11.42% at 1 mg ml^-1）. After pre-treatment with 0.03 mg ml^-1 of GBE, the relaxant effects of mirodenafil were increased at all concentrations, After tetraethylammonium （TEA） （1 mmol I^-1） administration, the increased effects were inhibited （P〈0.01）. Extracellular administration of GBE increased the whole-cell K^＋ outward currents in a dose-dependent fashion. The increase of the outward current was inhibited by I mmol 1-1 TEA. These results suggest that GBE could increase the relaxant potency of mirodenafil even at a minimally effective dose. The K＋ flow through potassium channels might be one of the mechanisms involved in this synergistic relaxation.展开更多
OBJECTIVE To find that the extracellular cap of a K2P channel can act as a new allosteric site and may serve as a direct drug target.METHODS Molecular biology and cell transfection,electrophysiology,molecular docking,...OBJECTIVE To find that the extracellular cap of a K2P channel can act as a new allosteric site and may serve as a direct drug target.METHODS Molecular biology and cell transfection,electrophysiology,molecular docking,molecular dynamics simulations,virtual screening for TREK1,and depressive-related behavior tests.RESULTS Extracellular domain of TREK1 channel existed a dynamic cavity in the extracellular domain by the method of computations,mutagenesis and electrophysiology.Molecular dynamics simulations suggested that ligand-induced allosteric conformational transitions lead to blockage of the ion conductive pathway.Using virtual screening approach,we identified other inhibitors targeting the extracellular allosteric ligand-binding site of these channels.Overall,our results suggested that the allosteric site at the extracellular cap of the K2P channels might be a promising drug target for these membrane proteins.The TREK1 inhibitor TKDC had significantly faster onset than that of fluoxetine in chronic administration trials,and the study confirms that TREK1 was an important target for the development of rapid antidepressants.CONCLUSION The study is a significant step forward for understanding the function of TREK and for identifying specific inhibitors,which should be of interest to others in the field.展开更多
对humanether-a-gò-gò related genes(HERG)钾离子通道(钾通道)抑制剂,计算了表征分子组成、电荷分布、拓扑、几何结构及物理化学性质等特征的1559个分子描述符,采用Fischer Score(F-Score)排序过滤和MonteCarlo模拟退火法相...对humanether-a-gò-gò related genes(HERG)钾离子通道(钾通道)抑制剂,计算了表征分子组成、电荷分布、拓扑、几何结构及物理化学性质等特征的1559个分子描述符,采用Fischer Score(F-Score)排序过滤和MonteCarlo模拟退火法相结合从中筛选与HERG钾通道抑制剂分类相关的分子描述符.采用支持向量机(SVM)方法,分别以IC50=1.0、10.0μmol·L-1为分类标准,建立了三个分类预测模型.对367个训练集分子,用五重交叉验证,得到正、负样本的平均预测精度分别为84.8%-96.6%、80.7%-97.7%,其总的平均预测精度为87.1%-97.2%,优于其它文献报道结果.对97个外部测试集分子,所建三个模型的总样本预测精度在67.0%-90.1%之间,接近或优于其它文献报道结果.展开更多
目的:研究环加氧酶2(COX-2)抑制剂尼美舒利和COX-1抑制剂比罗昔康在对抗心肌氧化应激损伤中的作用及其机制。方法:离体大鼠心脏行Langendorff灌流,分别给予H2O2、pyrogallol(可产生超氧阴离子)或VitC+Fe2+(可产生羟自由基),观察心脏收...目的:研究环加氧酶2(COX-2)抑制剂尼美舒利和COX-1抑制剂比罗昔康在对抗心肌氧化应激损伤中的作用及其机制。方法:离体大鼠心脏行Langendorff灌流,分别给予H2O2、pyrogallol(可产生超氧阴离子)或VitC+Fe2+(可产生羟自由基),观察心脏收缩功能、心肌LDH和MDA含量。心肌COX的活性用PGI2的稳定产物6-Keto-PGF1α的含量表示。结果:尼美舒利(3mg/kg)可明显减轻H2O2引起的收缩功能下降(10min应激时LVDP为72%±10%vs61%±11%,P<0.05),减少LDH释放[(5.5±2.5)U/Lvs(8.0±2.1)U/L,P<0.05)]。而比罗昔康(3mg/kg)虽然能抑制H2O2应激时LVDP的下降(73%±10%vs61%±11%,P<0.05),却加重LVEDP的上抬[(29.00±5.61)mmHgvs(23.16±3.57)mmHg,P<0.01]。尼美舒利亦能减轻超氧阴离子和羟自由基引起的心肌损伤作用。尼美舒利和比罗昔康预处理对H2O2应激心肌6-Keto-PGF1α含量无明显影响。线粒体ATP敏感性钾通道(mitochondrial ATP sensitive potassium channel,mitoKATP)的阻断剂5-HD可取消尼美舒利减轻H2O2引起的LVDP和±dp/dtmax降低作用(分别为53%±12% vs 69%±3%、58%±11% vs 72%±7%和37%±8% vs 51%±4%,P<0.01)。结论:COX-2抑制剂尼美舒利可以对抗心肌氧化损伤,其机制通过非COX依赖性途径发挥作用,而mitoK可能参与尼美舒利的保护作用。展开更多
文摘In this study, we investigated the effects of a combination of Ginkgo biloba extracts （GBE） and phosphodiesterase type 5 （PDE-5） inhibitors on the muscular tone of the corpus cavernosum and potassium channel activity of corporal smooth muscle cells. Strips of corpus cavernosum from male New Zealand white rabbits were mounted in organ baths for isometric tension studies. After contraction with 1 × 10^-5 mol I^-1 norepinephrine, GBE （0.01-1 mg ml^-1） and mirodenafil （0.01-100 nmol I^-1） were added together into the organ bath. In electrophysiological studies, whole-cell currents were recorded by the conventional patch-clamp technique in cultured smooth muscle cells of the human corpus cavernosum. The corpus cavemosum was relaxed in response to GBE in a dose-dependent manner （from 0.64%±8.35% at 0.01 mg ml^-1 to 52.28%±11.42% at 1 mg ml^-1）. After pre-treatment with 0.03 mg ml^-1 of GBE, the relaxant effects of mirodenafil were increased at all concentrations, After tetraethylammonium （TEA） （1 mmol I^-1） administration, the increased effects were inhibited （P〈0.01）. Extracellular administration of GBE increased the whole-cell K^＋ outward currents in a dose-dependent fashion. The increase of the outward current was inhibited by I mmol 1-1 TEA. These results suggest that GBE could increase the relaxant potency of mirodenafil even at a minimally effective dose. The K＋ flow through potassium channels might be one of the mechanisms involved in this synergistic relaxation.
基金National Natural Science Foundation of China(3120077181030065+5 种基金8127405531371066013117101101)Ministry of Science and Technology(2013CB91060101)National Science Technology Major Project of China (2012ZX09301-001-062014ZX09102001-005).
文摘OBJECTIVE To find that the extracellular cap of a K2P channel can act as a new allosteric site and may serve as a direct drug target.METHODS Molecular biology and cell transfection,electrophysiology,molecular docking,molecular dynamics simulations,virtual screening for TREK1,and depressive-related behavior tests.RESULTS Extracellular domain of TREK1 channel existed a dynamic cavity in the extracellular domain by the method of computations,mutagenesis and electrophysiology.Molecular dynamics simulations suggested that ligand-induced allosteric conformational transitions lead to blockage of the ion conductive pathway.Using virtual screening approach,we identified other inhibitors targeting the extracellular allosteric ligand-binding site of these channels.Overall,our results suggested that the allosteric site at the extracellular cap of the K2P channels might be a promising drug target for these membrane proteins.The TREK1 inhibitor TKDC had significantly faster onset than that of fluoxetine in chronic administration trials,and the study confirms that TREK1 was an important target for the development of rapid antidepressants.CONCLUSION The study is a significant step forward for understanding the function of TREK and for identifying specific inhibitors,which should be of interest to others in the field.
文摘对humanether-a-gò-gò related genes(HERG)钾离子通道(钾通道)抑制剂,计算了表征分子组成、电荷分布、拓扑、几何结构及物理化学性质等特征的1559个分子描述符,采用Fischer Score(F-Score)排序过滤和MonteCarlo模拟退火法相结合从中筛选与HERG钾通道抑制剂分类相关的分子描述符.采用支持向量机(SVM)方法,分别以IC50=1.0、10.0μmol·L-1为分类标准,建立了三个分类预测模型.对367个训练集分子,用五重交叉验证,得到正、负样本的平均预测精度分别为84.8%-96.6%、80.7%-97.7%,其总的平均预测精度为87.1%-97.2%,优于其它文献报道结果.对97个外部测试集分子,所建三个模型的总样本预测精度在67.0%-90.1%之间,接近或优于其它文献报道结果.
文摘目的:研究环加氧酶2(COX-2)抑制剂尼美舒利和COX-1抑制剂比罗昔康在对抗心肌氧化应激损伤中的作用及其机制。方法:离体大鼠心脏行Langendorff灌流,分别给予H2O2、pyrogallol(可产生超氧阴离子)或VitC+Fe2+(可产生羟自由基),观察心脏收缩功能、心肌LDH和MDA含量。心肌COX的活性用PGI2的稳定产物6-Keto-PGF1α的含量表示。结果:尼美舒利(3mg/kg)可明显减轻H2O2引起的收缩功能下降(10min应激时LVDP为72%±10%vs61%±11%,P<0.05),减少LDH释放[(5.5±2.5)U/Lvs(8.0±2.1)U/L,P<0.05)]。而比罗昔康(3mg/kg)虽然能抑制H2O2应激时LVDP的下降(73%±10%vs61%±11%,P<0.05),却加重LVEDP的上抬[(29.00±5.61)mmHgvs(23.16±3.57)mmHg,P<0.01]。尼美舒利亦能减轻超氧阴离子和羟自由基引起的心肌损伤作用。尼美舒利和比罗昔康预处理对H2O2应激心肌6-Keto-PGF1α含量无明显影响。线粒体ATP敏感性钾通道(mitochondrial ATP sensitive potassium channel,mitoKATP)的阻断剂5-HD可取消尼美舒利减轻H2O2引起的LVDP和±dp/dtmax降低作用(分别为53%±12% vs 69%±3%、58%±11% vs 72%±7%和37%±8% vs 51%±4%,P<0.01)。结论:COX-2抑制剂尼美舒利可以对抗心肌氧化损伤,其机制通过非COX依赖性途径发挥作用,而mitoK可能参与尼美舒利的保护作用。
