Objective To study the effect of allitridum on the transient outward potassium current （Ito） of ventricular myocytes in heart failure （HF）. Methods The dual enzymatic method was used to separate single ventricular...Objective To study the effect of allitridum on the transient outward potassium current （Ito） of ventricular myocytes in heart failure （HF）. Methods The dual enzymatic method was used to separate single ventricular myocytes from Sprague Dawley rats. Patch-clamping was used to record Ito and analyze the effect of allitridum on the current. Results The Ito current had a significant decrease in the HF group, compared with the control group. The density of Ito in the HF group was increased after treatment of allitridum （30 μmol/L）. The peak current densities of Ito were enhanced in the HF group from 6.01 ±0.30 pA/pF to 8.41 ±0.54 pA/pF （P 〈 0.01） at ＋50 mV after treatment with allitridum （30 μmol/L）. We also determined the effect of allitridum on the gating mechanism of the Ito in the HF group. Conclusions We found that allitridum increased the Ito by accelerating the activation of channels and shortened the time constants of inactivation, and allitridum decreased the remodeling of Ito in ventricular myocytes of rats with HF.展开更多
Objective: Previous studies have shown t hat allitridum can protect myocardium from ischemia/reperfusion (I/R) injury, bu t whether allitridum had the effect of anti-apoptosis is unclear. The aim of th is study was t...Objective: Previous studies have shown t hat allitridum can protect myocardium from ischemia/reperfusion (I/R) injury, bu t whether allitridum had the effect of anti-apoptosis is unclear. The aim of th is study was to investigate whether allitridum had the effects of pharmacologica l preconditioning and decreasing myocardium apoptosis after ischemic insult. Methods: Pentobarbital sodium-anesthetized Sprague-Dawley (SD) rats underwent 30 min of left anterior descending (LAD) coronary occlusion foll owed by 120 min of reperfusion. Thirty-six rats were divided into three groups randomly: Control group, I/R group and allitridum (G) group. The control and I/R groups with saline, G group with allitridum were administrated 24 h before oper ation. Control group underwent only sham operation; the other two groups underwe nt I/R operation. Infarcted size (IS/AAR %) was measured in I/R and G groups. Ma londialdehyde (MDA), Creatine kinase isoenzyme-MB (CK-MB ), Superoxide dismuta se (SOD)and the apoptosis index (AI) by TUNEL staining were measured in each gro up. In addition, DNA fragmentation by agarose gel electrophoresis was conducted on DNA isolated from these groups. Results: Allitridum p retreatm ent decreased the infarcted size compared with I/R group in IS/ AAR%[(21.85±1. 49)% vs. ( 44.65±4.65)%, P<0.01], CK-MB [(986.40±94.01) vs. (2044.2 5±1 07.28) U/L, P<0.01] and MDA [(3.26±0.35) vs. (4.96±0.46) nmol/mg pro, P<0.01], and SOD level in G group was higher than that of I/R group [(140 .20±12.89)vs. (73.16±11.22) U/mg pro, P<0.01]. AI of I/R group was highe r than that of G group [(13.99±3.05)% vs. (6.97±1.23)%, P<0.01], which was consistent with that in DNA fragmentation by agarose gel electrophoresis. Conclusion: This study indicated that allitridum had the effect of protecting myocardium against I/R injury and decreasing infarcted zone. The e ffect was probably through decreasing myocardium apoptosis in I/R injury.展开更多
目的研究大蒜素对HEK293细胞HERG电流的作用,探讨其抗心律失常的可能机制。方法采用瞬时转染的方法,将HERG通道质粒转入HEK293细胞上,应用细胞外局部灌流法于膜片钳高阻抗封接形成后给予大蒜素,使其终浓度为30μmol/L。室温下,采用全细...目的研究大蒜素对HEK293细胞HERG电流的作用,探讨其抗心律失常的可能机制。方法采用瞬时转染的方法,将HERG通道质粒转入HEK293细胞上,应用细胞外局部灌流法于膜片钳高阻抗封接形成后给予大蒜素,使其终浓度为30μmol/L。室温下,采用全细胞膜片钳技术在电压钳形模式下记录电流和门控动力学,观察大蒜素对HERG电流的作用。结果 30μmol/L大蒜素对正常大鼠心室肌细胞HERG电流有显著的阻滞效应,使其尾电流密度由73.5±4.3 p A/p F降低至42.1±3.6 p A/p F(P<0.01,n=14)。其作用呈浓度依赖性。半数抑制浓度为34.74μmol/L,Hill系数为1.01。大蒜素可使HERG的电流-电压曲线降低,且随着去极化电位的增加,作用更加明显,提示其作用具有电压依赖性,门控机制研究发现大蒜素可以使通道激活曲线向更正的方向移动,进而延迟激活;使通道稳态失活更负的方向移动,导致失活加速。同时,使通道灭活的慢时间常数缩短,从而加速通道的灭活。结论大蒜素抑制HEK293细胞上HERG电流,提示这可能是其治疗心律失常的细胞电生理基础。展开更多
基金Acknowledgments This work was supported by the National Natural Science Foundation of China （No： 81170177, 81030002 and 8147054）. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. There is no competing interest to declare.
文摘Objective To study the effect of allitridum on the transient outward potassium current （Ito） of ventricular myocytes in heart failure （HF）. Methods The dual enzymatic method was used to separate single ventricular myocytes from Sprague Dawley rats. Patch-clamping was used to record Ito and analyze the effect of allitridum on the current. Results The Ito current had a significant decrease in the HF group, compared with the control group. The density of Ito in the HF group was increased after treatment of allitridum （30 μmol/L）. The peak current densities of Ito were enhanced in the HF group from 6.01 ±0.30 pA/pF to 8.41 ±0.54 pA/pF （P 〈 0.01） at ＋50 mV after treatment with allitridum （30 μmol/L）. We also determined the effect of allitridum on the gating mechanism of the Ito in the HF group. Conclusions We found that allitridum increased the Ito by accelerating the activation of channels and shortened the time constants of inactivation, and allitridum decreased the remodeling of Ito in ventricular myocytes of rats with HF.
文摘Objective: Previous studies have shown t hat allitridum can protect myocardium from ischemia/reperfusion (I/R) injury, bu t whether allitridum had the effect of anti-apoptosis is unclear. The aim of th is study was to investigate whether allitridum had the effects of pharmacologica l preconditioning and decreasing myocardium apoptosis after ischemic insult. Methods: Pentobarbital sodium-anesthetized Sprague-Dawley (SD) rats underwent 30 min of left anterior descending (LAD) coronary occlusion foll owed by 120 min of reperfusion. Thirty-six rats were divided into three groups randomly: Control group, I/R group and allitridum (G) group. The control and I/R groups with saline, G group with allitridum were administrated 24 h before oper ation. Control group underwent only sham operation; the other two groups underwe nt I/R operation. Infarcted size (IS/AAR %) was measured in I/R and G groups. Ma londialdehyde (MDA), Creatine kinase isoenzyme-MB (CK-MB ), Superoxide dismuta se (SOD)and the apoptosis index (AI) by TUNEL staining were measured in each gro up. In addition, DNA fragmentation by agarose gel electrophoresis was conducted on DNA isolated from these groups. Results: Allitridum p retreatm ent decreased the infarcted size compared with I/R group in IS/ AAR%[(21.85±1. 49)% vs. ( 44.65±4.65)%, P<0.01], CK-MB [(986.40±94.01) vs. (2044.2 5±1 07.28) U/L, P<0.01] and MDA [(3.26±0.35) vs. (4.96±0.46) nmol/mg pro, P<0.01], and SOD level in G group was higher than that of I/R group [(140 .20±12.89)vs. (73.16±11.22) U/mg pro, P<0.01]. AI of I/R group was highe r than that of G group [(13.99±3.05)% vs. (6.97±1.23)%, P<0.01], which was consistent with that in DNA fragmentation by agarose gel electrophoresis. Conclusion: This study indicated that allitridum had the effect of protecting myocardium against I/R injury and decreasing infarcted zone. The e ffect was probably through decreasing myocardium apoptosis in I/R injury.
文摘目的研究大蒜素对HEK293细胞HERG电流的作用,探讨其抗心律失常的可能机制。方法采用瞬时转染的方法,将HERG通道质粒转入HEK293细胞上,应用细胞外局部灌流法于膜片钳高阻抗封接形成后给予大蒜素,使其终浓度为30μmol/L。室温下,采用全细胞膜片钳技术在电压钳形模式下记录电流和门控动力学,观察大蒜素对HERG电流的作用。结果 30μmol/L大蒜素对正常大鼠心室肌细胞HERG电流有显著的阻滞效应,使其尾电流密度由73.5±4.3 p A/p F降低至42.1±3.6 p A/p F(P<0.01,n=14)。其作用呈浓度依赖性。半数抑制浓度为34.74μmol/L,Hill系数为1.01。大蒜素可使HERG的电流-电压曲线降低,且随着去极化电位的增加,作用更加明显,提示其作用具有电压依赖性,门控机制研究发现大蒜素可以使通道激活曲线向更正的方向移动,进而延迟激活;使通道稳态失活更负的方向移动,导致失活加速。同时,使通道灭活的慢时间常数缩短,从而加速通道的灭活。结论大蒜素抑制HEK293细胞上HERG电流,提示这可能是其治疗心律失常的细胞电生理基础。
基金supported in part by the Laboratory of Pathology,Immunology and Molecular Biology and Animal Center of Tongji Medical college of Huazhong University of Science and Technology
