刺五加叶皂甙单体Sb对培养大鼠心肌细胞动作电位的影响

本研究中所用的刺五加叶皂甙单体Ｓｂ（５０，２００μｇ／ｍＬ），使培养的Ｗｉｓｔａｒ大鼠心肌细胞动作电位的波幅，波宽，阈电位，最大舒张电位，超射，最大除极速度及复极（１０％，５０％，９０％）水平的动作电位波宽一致减小。Ｃａ＾２＾＋８０μｇ／ｍＬ能使之反转，Ｓｂ作用与尼莫地平作用相似。上述结果表明Ｓｂ具有钙通道阻滞作用。     

刺五加叶皂甙单体S_c1对培养大鼠心肌细胞自发性搏动及动作电位的影响／

培养Ｗｉｓｔａｒ大鼠乳鼠心室肌细胞，向培养基中分别加入浓度为５０μｇ／ｍＬ至８００μｇ／ｍＬ的刺五加叶皂甙单体（ＡｃａｎｔｈｏｐａｎａｘｓｅｎｔｉｃｏｓｉｄｅｓＣ１，Ｓｃ１），可使心肌细胞的自发性搏动呈剂量依赖性抑制，洗脱后能使之得以恢复。向培养基中加入１００μｇ／ｍＬＳｃ１，使培养的Ｗｉｓｔａｒ大鼠心肌细胞动作电位的波幅、波宽、阈电位、最大舒张电位、最大除极速度及复极（１０％、５０％、９０％）水平的动作电位波宽一致减小。Ｃａ２＋８０μｇ／ｍＬ能使之反转。Ｓｃ１作用与０．４μｇ／ｍＬ尼莫地平作用相似。上述结果表明Ｓｃ１具有钙通道阻滞作用。     

西洋参茎叶皂甙对培养的大鼠心肌细胞动作电位的影响

西洋参茎叶皂甙（POS250、500μg/ml）使培养的Wistar大鼠心肌细胞动作电位的波幅、波宽、阀电位、最大舒张电位、最大除极速度及复极50％水平的动作电位波宽一致减小。实验结果表明，PQS可能具有钙通道阻滞作用。     

西洋参茎叶皂甙湖养的大鼠心肌细胞动作电位的影响

西洋参茎叶皂甙(PQS250、500μg/ml)使培养的Wistar大鼠心肌细胞动作电位的波幅、波宽、阈电位、最大舒张电位、最大除极速度及复极50％水平的动作电位波宽一致减小。实验结果表明,ROS可能具有钙通道阻滞作用。     

黄芪皂甙对培养心肌细胞跨膜电活动与自发性搏动的影响

培养Ｗｉｓｔａｒ大鼠乳鼠的心肌细胞。向培养基中加入黄芪皂甙５００μｇ·ｍＬ－１使搏动的心肌细胞群落数目增多；心肌细胞动作电位的发放频率增高，波幅、波宽、超射、最大舒张电位、阈电位、最大除极速度等各项参数减小；心肌细胞膜的静息电位减小１０ｍＶ。洗脱后恢复。以上结果表明黄芪皂甙能抑制Ｎａ－Ｋ－ＡＴＰ酶。     

用斑点免疫结合法测定登革病毒单克隆抗体亲和力

建立斑点免疫结合法（ＤＩＡ）测定抗体相对亲和力。用此法出定了登革病毒Ⅱ型非结构蛋白ＮＳ１四株单克隆抗体（ＭｃＡｂｓ）的相对亲和力，４株ＭｃＡｂｓ对ＮＳ１的亲和力各不相同。按５０％最大结合浓度分析，抗体株６─１／Ｃ为０．０５μｇ／ｍｌ．１─７／Ｆ为０．６７μｇ／ｍｌ．５Ｄ为２５．００μｇ／ｍｌ，３─１１／Ｃ为５７．００μｇ／ｍｌ。以上结果为应用这些单克隆抗体提供了依据。同时，说明用ＤＩＡ法测定ＭｃＡｂ相对亲和力的可行性。     

黄芪皂甙对培养心肌细胞跨膜电活动与自发性搏动的影响

培养Ｗｉｓｔａｒ大鼠乳鼠的心肌细胞。向培养基中加入黄芪皂甙５００μｇ．ｍＬ＾－＾１使搏动的心肌细胞群落数目增多；心肌细胞动作电位的发放频率增高，波幅，波宽，超射，最大舒张电位，阈电位，最大除极速度等各项参数减小；心肌细胞膜的静息电位减小１０ｍＶ。洗脱后恢复。以上结果表明黄氏皂甙能抑制Ｎａ－Ｋ－ＡＴＰ酶。     

用斑眯免疫结合法测定登革病毒单克隆抗体亲和力

建立斑点免疫结合法（ＤＩＡ）测定抗体相对亲和力，用此法测定了登革病毒Ⅱ型非结构蛋白ＮＳ１四株单克隆抗体（ＭｃＡｂａ）的相对亲和力，４株ＭｃＡｂｓ对ＮＳ１的亲和力各不相同，按５０％最大结合浓度分析，抗体株６－１／Ｃ为０．０５μｇ／ｍｌ。１－７／Ｆμｇ／ｍｌ，５Ｄ为２５．００μｇ／ｍｌ。３－１１／Ｃ为５７．０μｇ／ｍｌ。以上结果为应用单克隆抗体提供了依据。同时，说明用ＤＬＡ法测定ＭｃＡｂ相对亲和力的可     

环丙沙星注射液的抗菌作用

环丙沙星注射液对常见致病菌的ＭＩＣ为：绿脓杆菌０．６２５μｇ／ｍＬ，大肠杆菌０．０３９μｇ／ｍＬ，脑膜炎球菌０．３１３μｇ／ｍＬ，金黄色葡萄球菌０．６２５μｇ／ｍＬ，伤寒杆菌０．０３９μｇ／ｍＬ，肺炎球菌０．１２５μｇ／ｍＬ，溶血性链球菌０．６２５μｇ／ｍＬ．环丙沙星注射液对常见致病菌的ＭＢＣ为：绿脓杆菌２．５μｇ／ｍＬ，脑膜炎球菌１．２５μｇ／ｍＬ，大肠杆菌０．１５６μｇ／ｍＬ，伤寒杆菌０．１５６μｇ／ｍＬ，肺炎球菌２．５μｇ／ｍＬ，溶血性链球菌１．２５μｇ／ｍＬ，金黄色葡萄球菌１．２５μｇ／ｍＬ．体内感染治疗试验对接种大肠杆菌０．５×０７个／只静脉给药的ＥＰ５０为（０．７８７±０．１２９）ｍｇ／ｋｇ，对接种肺炎链球菌０．８×１０６个／只静脉给药的ＥＰ５０为（３．３１３±０．５６７）ｍｇ／ｋｇ．     

黄芪皂甙对离体工作心脏的强心作用

本实验中，高浓度黄芪皂甙（５０、１００、２００μｇ／ｍＬ使Ｗｉｓｔａｒ大鼠离体工作心脏的心肌收缩性能立即呈剂量依赖性增强，作用与毒毛旋花子甙Ｋ（０．７２μｇ／ｎＬ）相似；低浓度黄芪皂甙（３０μｇ／ｍＬ），使心肌收缩性能立即减弱，提高细胞外钙不能反转此效应；洗脱后，黄芪皂甙的作用迅速消失。以上结果表明，黄茂皂戒对心肌有正性肌力作用，与强心甙类药物相似。     

大豆总皂甙对培养心肌细胞自发性搏动与动作电位的影响

培养Wistar大鼠乳鼠的心室肌细胞,向培养基中分别加入浓度为1.56μg/ml至50μg/ml的大豆皂甙,可使心肌细胞群落的自发性搏动呈剂量依赖性抑制。洗脱大豆皂甙或向培养基中再加入10μg/ml肾上腺素均能使自发性搏动恢复。向培养基中加入大豆皂甙5μg/ml使心肌细胞动作电位的波幅、波宽、超射、最大舒张电位、阈电位、最大除极速度等各电参数立即减小。Ca~(2+)80μg/ml能使动作电位的抑制逆转。上述结果表明大豆皂甙对培养的鼠心肌细胞具有钙通道阻滞用。     

阿魏酸钠对豚鼠心室肌动作电位的影响

用普通玻璃微电极细胞内记录,观察阿魏酸钠对豚鼠心室肌细胞动作电位、有效不应期的影响,3种浓度的阿魏酸钠溶液(0.1mg/mL,0.2mg/mL,0.4mg/mL)分别灌流30min,动作电位幅值(APA)和复极20％时程(APD_(20))无明显改变,但复极90％处动作电位时程(APD_(20))与有效不应期延长,浓度在0.1mg/mL和0.2mg/mL时,药物可延长复极50％处的动作电位时程(APD_(50))。     

炙甘草汤对低钾诱发家兔心律失常的电生理影响

目的：研究炙甘草汤对低钾诱发家兔心律失常的电生理影响。方法：应用常规的玻璃微电极细胞内记录技术，观察炙甘草汤对低钾诱发家兔心律失常的动作电位0相幅值（APA），动作电位时程（APD），50％复极化时间（APD50），90％复极化时uj （APD90），最大舒张电位（MDP），4相自动去极速度（Vmax），自发放电频率（RPF）的影响。结果：（1）用20mg／mL的炙甘草汤灌流心室肌细胞后与模型对照组相比细胞电生理变化不明显。（2）用40mg／mL的炙甘草汤灌流心室肌细胞后与模型对照组相比动作电位时程（APD）缩短（P〈0．05），90％复极化时间（APD90）缩短（P〈0.05）。（3）用80mg／mL的炙甘草汤灌流心室肌细胞后与模型对照组相比动作电位时程（APD）明显缩短（P〈0.01），50％复极化时间（APD50）、90％复极化时间（APD90）缩短（P〈0.05）。（4）用80mg／mL的炙甘草汤灌流左心室流出道慢反应自律细胞后与模型对照组相比自发放电频率下降（P〈0.05）。结论：炙甘草汤能缩短动作电位时程、50％及90％复极化时间，降低自发放电频率，并能防治低钾诱发的心律失常的发生。     

Na+/Ca2+ exchanger current and K+ current remodeling in midmyocardial cells of hypertrophic left ventricle]

OBJECTIVE: To investigate the characteristics of Na+/Ca2+ exchanger current (INa+ /Ca2+) and K+ current remodeling in midmyocardial cells of hypertrophic left ventricle for understanding the ionic basis of arrhythmia of the hypertrophic heart. METHODS: Twenty New Zealand rabbits were divided equally into normal control group and operation group, and in the latter, left ventricular hypertrophy was induced in the rabbits by partial ligation of the abdominal aorta. Action potentials, INa+/Ca2+, slowly activating delayed rectifier K+ current (IKs) and rapidly activating delayed rectifier K+ current (IKr) were recorded in the two groups by using whole-cell patch-clamp technique. RESULTS: At the basic cycle length of 2 s, 90% action potential duration (APD90) in control and operation groups was 522.0+/-19.5 ms (n=6) and 664.7+/-32.7 ms (n=7) respectively; at the testing potential of +40 mV, outward INa+/Ca2+ density in the two groups was 0.94+/-0.11 pA/pF (n=9) and 1.30+/-0.11 pA/pF (n=8) respectively; the testing potential of -100 mV elicited inward INa+/Ca2+ density of 0.40+/-0.05 pA/pF (n=9) and 0.56+/-0.02 pA/pF (n=8) respectively. The testing potential of +50 mV induced IKs tail current density of 0.26+/-0.03 pA/pF (n=8) and 0.17+/-0.01 pA/pF (n=9), and IKr tail current density of 0.34+/-0.02 pA/pF (n=8) and 0.23+/-0.02 pA/pF (n=9) respectively. Statistically significant differences were identified between the control and operation groups in all the above indices measured. CONCLUSION: The characteristics of electrical remodeling changes in midmyocardial cells of hypertrophic left ventricle, exhibited by prolonged action potential, up-regulated INa+/Ca2+ and down-regulated IKs and IKr.     

新型正性肌力药物维纳利酮对离体犬心室乳头肌细胞...

This study adopted intracellular microelectrode technic to observe the effect of OPC-8212 (Vesnarinone) on intracellular potential of isolated canine ventricular papillary muscle. The record and data processing were completed by computerized intellective instrument designed by ourselves. The results of intracellular record in 14 canine ventricular papillary muscle showed no significant change in the resting potential (RP), amplitude of action potential (APA) and maximum depolarize velocity of 0 phase (Vmax). But significantly increased whole duration of action potential (APT). The duration of repolarization to 1/3 (APD 1/3) and to 2/3 (APD 2/3) significantly increased too. The plateau phase raised. These results suggest that K+ permeability at resting myocardiac cell membrane may have not been effected by OPC-8212. Activation of the fast sodium channel may have not been effected too. The results of our studies also suggest that inward flow of Ca2+ increased. The delayed outward K+ (Ik) and the inward, rectifying K+ current (Ik1) possible decreased. Thus, the OPC-8212 might become a nonglucoside and noncatecholamine new positive inotropic drug.     

敲除Annexin A7基因的小鼠早期胚胎心肌细胞钙稳态正常

目的:研究Annexin A7在早期胚胎发育过程中对钙平衡调节的作用. 方法: 利用钙成像技术和膜片钳技术检测敲除Annexin A7小鼠的早期胚胎心肌细胞的钙平衡以及相应的离子通道的特性. 结果: 在胚胎心肌细胞发育的早期,敲除Annexin A7小鼠胚胎心肌细胞的静息钙(340/380荧光比例 0.78±0.02)、钙峰值(340/380荧光比例1.28±0.05)和正常细胞的值相似;动作电位(APD90 242.7±43.7 ms、最大去极化电位56.8±1.7 mV)以及L-型钙电流密度(14.1±2.5 pA/pF)和正常细胞的相似,并且钙电流能被碳酰胆碱减小(51.7±8)%,也和正常细胞相似. 结论: 敲除Annexin A7基因的小鼠早期胚胎心肌细胞具有正常的钙稳态以及正常的离子通道.     

Na+/Ca2+交换体电流在兔左心室壁分布的异质性

目的探讨Na+/Ca2+交换体电流(INa+/Ca2+)在左室肌不同部位的分布特征及其与跨壁复极异质性的关系.方法采用全细胞膜片钳技术,分别记录兔左心室肌内膜下、中层及外膜下细胞的动作电位(AP)、INa+/Ca2+及IK.结果中层细胞AP时程明显长于外膜下细胞(P<0.01);在+40 mV时,外向INa+/Ca2+密度在中层细胞明显大于外膜下及内膜下细胞(P分别＜0.01,0.05);在-100 mV时,内向INa+/Ca2+密度在中层细胞明显大于外膜下(P<0.05);在测试电压为+50mV时,中层细胞的IKs尾电流密度明显小于外膜下细胞(P<0.05), 内膜下、中层及外膜下细胞的IKr尾电流密度无明显区别(P>0.05).结论 INa+/Ca2+与IKs在兔左室肌的分布具有异质性,并导致了跨壁复极异质性的形成.     

丹参素对缺氧/缺糖损伤神经细胞线粒体的保护作用

目的观察丹参素对SH-SY5Y细胞缺氧/缺糖损伤时胞浆内[Ca2 ]i、细胞凋亡率、细胞活性和线粒体膜电位的变化,探讨其对神经细胞线粒体的保护作用及其可能的机理.方法应用细胞培养、四唑盐比色实验(MTT)检测细胞活力,流式细胞术检测细胞内[Ca2 ]i、细胞凋亡百分率和线粒体膜电位.结果 SH-SY5Y细胞缺氧/缺糖损伤2 h时,细胞内[Ca2 ]i明显增加,为8.46 nmol/L(P<0.01),细胞凋亡率明显增高,为18.59% (P<0.01),细胞内[Ca2 ]i的浓度4 h时达到高峰,为9.89 nmol/L(P<0.01),而后呈下降趋势,细胞凋亡率随缺氧/缺糖损伤时间的延长而明显增高12 h时达到45.91%,细胞经缺氧/缺糖处理2 h后,线粒体膜电位和细胞活性分别降低29.17%(P<0.01)、38.80%(P<0.01),随着缺氧/缺糖时间的延长线粒体膜电位和细胞活性进一步下降, 12 h时分别降低56.72%(P<0.01)、63.58%(P<0.01),丹参素能显著降低细胞内[Ca2 ]i,抑制细胞凋亡的发生,提高细胞活性和线粒体膜电位,与缺氧/缺糖组相比均有显著性差异(P<0.05,P<0.01).结论丹参素可抑制缺氧/缺糖损伤所致的线粒体膜电位的降低,从而具有稳定线粒体膜电位的作用,抑制细胞凋亡的发生,这种作用可能与其能抑制神经细胞内钙超载有关.     

Effects of benactyzine on action potentials and contractile force of guinea pig papillary muscles

ＩＮＴＲＯＤＵＣＴＩＯＮＢｅｎａｃｔｙｚｉｎｅｉｓａｓｙｎｔｈｅｔｉｃｂｌｏｃｋｅｒｏｆＭ ｒｅｃｅｐｔｏｒｐｏｓ ｓｅｓｓｉｎｇｓｍｏｏｔｈｍｕｓｃｌｅｒｅｌａｘａｎｔｐｒｏｐｅｒｔｉｅｓａｎｄｑｕｉｎｉｄｉｎｅ ｌｉｋｅａｃｔｉｏｎｏｎｈｅａｒｔ[1] .Ｂｅｎａｃｔｙｚｉｎｅｉｓｅｆｆｅｃｔｉｖｅｉｎｒｅｓｔｏｒ ｉｎｇｃｉｒｃｕｌａｔｏｒｙｆｕｎｃｔｉｏｎｄｉｓｔｕｒｂｅｄｂｙｏｒｇａｎｏｐｈｏｓｐｈａｔｅｐｏｉ ｓｏｎｉｎｇ[2 ,3] .Ｐｒｅｖｉｏｕｓｓｔｕｄｉｅｓｓｕｇｇｅｓｔｅｄｔｈａｔｂｅｎａ…     

B-type natriuretic peptide modulates the action potential and the L-type calcium current in adult rat heart muscle cells

Natriuretic peptides seem to be a potent regulator of cell Ca2+ signalling in their action on the cardiovascular system. It was therefore the aim of this study to investigate the effect(s) of B-type natriuretic peptide (BNP) on the action potential and the L-type calcium current (I(CaL)) in the rat left ventricular myocytes. Perforated and whole cell patch clamp technique was used to record action potential (AP) and I(CaL) in current and voltage clamp mode, respectively. At the concentration tested of 10(-7) M, BNP significantly increased the action potential duration at 50% and at 90% of repolarization by 16.85% and 1639% respectively, and the phase II slope of the AP by 52.5%; reduced the I(CaL) amplitude with a 16.17% decrease in the peak amplitude; reduced (16.51%) the inactivation time course of current decay; increased the V0.5 activation of the L-type calcium channel by 32.84% and decreased V0.5 inactivation by 34.39%. These data suggest that BNP modulates cardiomyocyte function by reducing I(CaL) and modifying the AP. This study may show a novel facet to evaluate the paracrine/autocrine effect of BNP on the normal heart function.