苦参总碱抗实验性心律失常的作用

目的：研究苦参总碱抗实验性心律失常的作用。方法：本研究采用冠脉结扎，BaCl2肾上腺素，乌头碱，哇巴因诱发的心律失常模型。结果：苦参总碱能明显对抗大鼠冠脉结扎后诱发的早期缺血性心律失常；对BaCl2诱发的大鼠心律失常有预防和治疗作用；缩短静注肾上腺素诱发的家兔心律失常持续时间；增加乌头碱诱发大鼠心律失常的剂量；增加哇巴因诱发豚鼠心律失常的剂量。结论：苦参总碱对多种心律失常模型有预防或治疗作用，其抗心律失常机制是多方面的。     

氧化苦参碱抗大鼠实验性心律失常的作用探讨

目的观察氧化苦参碱的抗心律失常作用。方法将SD大鼠随机分为两组,制作乌头碱诱发大鼠室性心律失常模型和结扎左冠状动脉前降支诱发的大鼠室性心律失常,以及对氯仿所致大鼠的室颤,一组静脉注射生理盐水,另一组静注氧化苦参碱,观察两组心律失常的变化。结果氧化苦参(OM)20 mg/kg能明显对抗乌头碱和结扎左冠状动脉前降支诱发的大鼠室性心律失常,也能预防对氯仿所致小鼠的室颤的发生。结论氧化苦参碱对大鼠有明显的抗心律失常作用,此实验为氧化苦参碱的临床应用提供了实验依据。     

蛇床子素抗心律失常作用实验研究

蛇床子素（Ｏｓｔ）对氯仿诱发的小鼠室颤、氯化钙诱发的大鼠室颤均有明显的预防作用，对乌头碱诱发的大鼠心律失常有明显的治疗效果，且能明显提高兔心室电致颤阈。这些结果均表明Ｏｓｔ有抗心律失常作用，并揭示其对钠、钙通道有一定的阻断作用。     

毛果芸香碱对实验性心律失常的保护作用

目的：观察毛果芸香碱对实验性心率失常的影响。方法：分别以乌头碱，氯化钡和哇巴因制备实验性动物心律失常模型，观察毛果芸香碱的干预作用。结果：毛果芸香碱可显著延迟乌头碱引起的大鼠室性心律失常的出现（P〈0．05），延长出现心律失常后的存活时间（P〈0．05）；能明显延迟氯化钡引起的大鼠双相室性心律失常的出现（P〈0．01），缩短心律失常的持续时间（P〈0．01）；能显著延长哇巴因引起豚鼠出现心律失常后的存活时间（P〈0．05）。毛果芸香碱的上述作用可被M3受体阻断荆4-DAMP完全逆转。结论：毛果芸香碱具有对抗乌头碱和氯化钡诱发大鼠，哇巴因诱发豚鼠心律失常的作用，提示其具有良好的抗心律失常作用；毛果芸香碱通过激动大鼠和豚鼠心肌M3受体而产生抗心律失常的作用。     

胃复安对实验性心律失常的作用

MCP有对抗氯化钡诱发大白鼠心律失常的作用;对抗氯仿-肾上腺素诱发家兔的心律失常,能提高乌头碱诱发大鼠心律失常的用量、致室颤量和致死量、但对哇巴因诱发的心律失常无影响,不能改善结扎大白鼠冠状动脉造成的缺血性心律失常。有局部麻醉作用。     

胆碱对乌头碱和哇巴因所诱发的心律失常的保护作用

目的探讨胆碱对乌头碱和哇巴因所诱发的心律失常的保护作用。方法大鼠和豚鼠分别注射乌头碱或哇巴因制备心律失常模型,观察预先给予低剂量(5 mg.kg-1)和高剂量(20 mg.kg-1)的胆碱对心律失常的保护作用。结果给予胆碱可明显对抗乌头碱或哇巴因所诱发的心律失常,表现为明显延迟心律失常的出现,推迟动物死亡时间等。高剂量胆碱对心律失常的保护作用优于低剂量。结论胆碱对心律失常具有保护作用,高剂量的作用优于低剂量。     

苄普地尔抗心律失常作用

苄普地尔iv能明显提高乌头碱诱发大鼠心律失常用量及豚鼠心脏哇巴因中毒耐量;对BaCI_2、Adr诱发的实验性心律失常有明显对抗作用;对大鼠冠脉结扎复灌注引起的心律失常有保护作用。     

庚醇对乌头碱诱发大鼠心律失常的影响

目的:观察缝隙连接脱耦联剂庚醇对离体和在体大鼠模型乌头碱诱导心律失常的影响,以探讨庚醇抗心律失常的机理。方法:(1)在体大鼠实验模型:雄性SD大鼠麻醉后,经股静脉先注射庚醇,然后用微量注射泵恒速注入乌头碱,记录心电图,分别计算各组动物发生室早、室速、室颤及心脏停搏时乌头碱的用量;(2)离体大鼠实验模型:动物心脏用Langendorff系统进行离体灌流,以溶有乌头碱的K-H液诱发心律失常,以5×10-8和5×10-7mol/L两个浓度为中度和重度诱发心律失常的乌头碱的浓度,观察庚醇对乌头碱诱发的心律失常评分的影响。结果:庚醇既有致心律失常作用,又有抗心律失常作用。在体心脏庚醇减少出现室早时乌头碱的用量,提高出现心脏停搏时乌头碱的用量;在离体心脏,中度剂量庚醇具有抗快速心律失常作用,以0.4mmol/L浓度为最佳,并且无心脏停搏,但重度剂量庚醇(1.0mmol/L)本身就引起心脏停搏。结论:庚醇仅具有抗乌头碱诱发离体心脏的快速心律失常作用,对乌头碱诱发的其它心律失常作用不明显,这种作用与其对膜离子通道没有影响、降低动作电位的传导速度有关。     

茉莉根提取物抗实验性心律失常的研究

目的研究茉莉根提取物的抗实验性心律失常作用。方法取茉莉根提取物分别注入由氯仿诱发心室颤动的小鼠、乌头碱诱发心律失常的大鼠、氯化钙诱发心室颤动的大鼠和肾上腺素诱发心律失常的家兔体内,观察其对实验动物心律失常的影响。结果①茉莉根提取物(腹腔注射2.0mg/kg、3.0mg/kg)对氯仿诱发的小鼠心室颤动有明显的预防作用;②茉莉根提取物(静脉注射1.0mg/kg、1.5mg/kg)对乌头碱诱发的大鼠心律失常有明显的治疗效果;③茉莉根提取物(静脉注射2.0mg/kg、3.0mg/kg)对氯化钙诱发的大鼠心室颤动具有预防作用,且能明显地降低大鼠的死亡率;④茉莉根提取物(静脉注射2.0mg/kg、3.0mg/kg)还能对抗肾上腺素诱发的家兔心律失常。以上作用具有明显的剂量依赖性。结论茉莉根提取物有明显的抗心律失常作用,可能与其抑制Na+内流、Ca2+内流及与阻断β-肾上腺素受体有关。     

M_3受体激动剂对氯化钡诱发大鼠心律失常的保护作用

目的观察M3受体激动剂胆碱和毛果芸香碱对氯化钡诱发Wistar大鼠心律失常的保护作用。方法舌下静脉注射氯化钡诱发Wistar大鼠心律失常,分别给予胆碱和毛果芸香碱以及M3受体特异阻断剂4-二苯乙酰氧-N-甲基哌啶甲碘化物(4-DAMP)干预,观察大鼠心律失常的发生和发展情况。结果氯化钡4mg·kg-1可诱发大鼠出现明显的双向性室性心律失常,胆碱10mg·kg-1和毛果芸香碱0.2mg·kg-1均能推迟双向性室性心律失常的出现,并使心律失常的持续时间缩短(P<0.01)、严重程度减轻(P<0.01)。胆碱和毛果芸香碱的上述作用又被M3受体阻断剂4-DAMP0.12μg·kg-1部分阻断(P<0.05)。结论胆碱和毛果芸香碱通过激动心肌M3受体,对氯化钡诱发Wistar大鼠心律失常的发生和发展具有保护作用。     

去葡萄糖竹节参皂苷Ⅳa抗实验性心律失常作用

目的研究去葡萄糖竹节参皂苷Ⅳa(DCⅣa)是否具有抗实验性心律失常的作用。方法采用氯化钡、乌头碱、毒毛花苷G及结扎左冠状动脉前降支诱发大鼠或豚鼠心律失常模型,八道生理记录仪观察并记录Ⅱ导联心电图,观察DCⅣa对实验性心律失常的预防作用。结果DCⅣa能缩短氯化钡和乌头碱诱发大鼠心律失常的持续时间,增加恢复正常心律的动物数;增加诱发豚鼠心律失常的毒毛花苷G用量;延长冠脉结扎致大鼠心律失常发生的潜伏期,缩短心律失常的持续时间,降低室颤发生的百分率。结论DCⅣa具有明显的抗心律失常作用。     

益气复脉合剂抗心律失常的实验研究

目的:证实益气复脉合剂的药理作用.方法:采用标准小鼠和健康大鼠,用氯仿、氯化钙、乌头碱造成动物心律失常模型,口服该合剂80 g.kg-1,观察动物的心律抑制或对抗作用.结果:益气复脉合剂对氯化钡、肾上腺引起的心律失常有明显的对抗作用,对氯仿、氯化钙引起心室纤颤致死有一定的保护作用.结论:该合剂为一个较好的抗心律失常新药.     

莲心总碱抗心律失常的实验研究

目的探讨莲心总碱对实验性心律失常的影响。方法采用乌头碱、毒毛花苷G、氯化钙、氯仿等4种药物诱发的动物心律失常及电刺激诱发家兔心室颤动（室颤）模型，运用在体心电图记录方法，观察莲心总碱的抗实验性心律失常作用。结果莲心总碱对药物及电刺激诱发的动物心律失常有明显对抗作用，可提高药物引起动物出现室性期前收缩、室性动过速、室颤的剂量，降低室颤发生率及死亡率。结论莲心总碱有较好的抗多种实验性心律失常作用，可能与其阻滞Na＋、Ca2＋内流，阻断折返作用有关。     

冬虫夏草对垂体后叶素所致大鼠缺血心肌的保护作用

目的　观察冬虫夏草对急性缺血心肌的保护作用。方法　采用垂体后叶素所致大鼠急性缺血模型观察药物的作用。结果　冬虫夏草和维拉帕米能明显缓解垂体后叶素所引起的心电图T波变化 (P <0 .0 1) ,垂体后叶素使 10 0 %的动物发生心律失常 ,而在冬虫夏草组及维拉帕米组 ,心律失常的发生律分别为 18% (P <0 .0 1)和 12 % (P <0 .0 1)。结论　冬虫夏草对垂体后叶素所致急性缺血心肌具有保护作用。     

一种新心律失常大鼠模型的建立

目的建立一种新的心律失常动物模型。方法大鼠脂肪乳剂灌胃建立大鼠高脂血症模型后进行冠状动脉结扎，观察术后1 h心律失常发生情况，并进行心律失常评分。结果高脂血症大鼠冠脉结扎组同正常大鼠冠脉结扎组相比，室性早博二联律、室性心动过速持续时间均明显延长。胺碘酮、维拉帕米对单纯冠脉结扎诱发的心律失常个数及持续时间无明显作用。维拉帕米对高脂血症大鼠冠脉结扎诱发的心律失常个数及持续时间也无明显影响，而胺碘酮明显减少高脂血症大鼠冠脉结扎诱发的心律失常个数及持续时间。结论通过高脂血症大鼠冠脉结扎可以建立一种接近临床的心律失常动物模型。     

Comparative study of the antiarrhythmic activity of L-, D-and DL-stereoisomers of potassium magnesium aspartate

Injection forms of potassium (K) and magnesium (Mg) aspartate (Asp) were compared in preventing cardiac disorders caused by electrolytic disturbances, primarily low K and Mg levels (e.g. caused by the treatment with cardiac glycosides and diuretic drugs). Widely used K- and Mg-Asp preparations (asparkam, panangin, pamaton) are synthesized from aspartic acid representing a racemic mixture of L- and D-stereoisomers. Differences in metabolism and utilization of D- and L-amino acids probably influence the pharmacological properties of K and Mg L- and D-aspartates. Moreover, the pharmacologically effective doses of Mg and K salts can induce toxicity, which depends on the nature of anions. The aim of this study was to compare of antiarrhythmic action of K and Mg L-, D-, and DL-Asp stereoisomers using calcium chloride (CaCl2) and aconitine induced arrhythmia models in rats and strophanthin-K induced arrhythmia model in guinea pigs. It was found that intravenously administered K- and Mg-L-Asp exhibited higher activity compared to K- and Mg-D- and DL-Asp on the strophanthin-K, CaCl2, and aconitine induced arrhythmia models. Indeed, K- and Mg-L-Asp more effectively decreased the incidence of arrhythmias, increased the time to onset of the first arrhythmia, decreased percentage loss of rats, and increased the survival life of animals after the first arrhythmia onset in rats with arrhythmias induced by strophanthin-K and CaCl2 as compared to K and Mg-D- and DL-Asp. At the same time K- and Mg-L-Asp was better than D- and DL-Asp with respect to acute toxicity (LD50), effective dose (ED50) and antiarrhythmic (therapeutic) ratio (LD50/ED50) in rats with aconitine-induced arrhythmia model.     

卡维地洛抗实验性心律失常作用

目的　评价卡维地洛（ＣＶＤ）抗实验性心律失常作用,并与β受体阻断剂普萘洛尔（ＰＲＯ） 进行比较。方法　采用氯仿致小鼠室颤（ＶＦ） , 哇巴因、乌头碱致豚鼠、大鼠心律失常,肾上腺素致豚鼠心律失常, 以及结扎大鼠冠状动脉诱发心律失常等５ 种模型。结果　与溶媒对照组相比, ＣＶＤ１ ｍｇ·ｋｇ－１ 显著降低氯仿诱发的小鼠ＶＦ 发生率〔１８－７５ ％（３／１６） ｖｓ８１－２５％ （１３／１６）,Ｐ＜ ０－０１〕,此作用与ＰＲＯ 相似。１ ｍｇ·ｋｇ－１ ＣＶＤ 和ＰＲＯ 均显著提高致室早（ＶＥ） , 室速（ＶＴ）, ＶＦ, 心搏停止（ＣＡ） 所需哇巴因和乌头碱用量（ Ｐ＜０－０１ ｖｓ 溶剂对照组） ;ＣＶＤ 对抗哇巴因的致心律失常作用较等剂量ＰＲＯ 显著（ Ｐ＜ ０－０１ ,ＣＶＤ ｖｓ ＰＲＯ）。ＣＶＤ 剂量依赖性地显著缩短ｉｖ 肾上腺素４０ μｇ·ｋｇ－ １ 所致心律失常持续时间,有效减少结扎冠脉诱发的缺血性心律失常ＶＴ,ＶＦ,ＣＡ 的发生率并缩短ＶＴ 的持续时间。结论　ＣＶＤ 具有抗多种实验性心律失常作用,该作用在等剂量时至少与ＰＲＯ 相近,或强于ＰＲＯ。ＣＶＤ的这种作用最终将有益于接受其治疗的原发性高血压、冠心病、充血性心力衰竭患者     

A possible mechanism of the antiarrhythmic action of glucagon

The effects of glucagon on ouabain-induced ventricular arrhythmias were studied in dogs with normal cardiac conduction systems and in dogs with surgically induced complete heart block. Glucagon, 20 μg/kg, effected conversion to a sinus rhythm in eight of nine animals with normal conduction systems, and in each instance the conversion occurred with a sinus tachycardia whose rate exceeded the rate of pre-existing ventricular arrhythmia. The one animal which failed to convert to a sinus rythm did not develop a sinus nodal rate faster than the rate of the ventricular arrhythmia. In 10 animals with ouabain-induced ventricular arrhythmias atrial pacing was employed to overdrive the arrhythmia, and in 6 cases this was successful. In all 6 experiments subsequent administration of glucagon after pacing resulted in conversion to a sinus rhythm at a rate greater than the minimum atrial pacing rate required to effect capture of the ventricules. In 4 of the 10 animals neither atrial overdrive nor glucagon were successful in effecting sinus conversion, but ventricular rate was slowed by lidocaine. In addition, in 5 animals with complete heart block and ouabain-induced ventricular tachycardia which were given glucagon, 20 μg/kg, there was no change in the tachycardia and no change in the ECG pattern associated with the arrhythmia. It was concluded that the antiarrhytmic action of glucagon in this arrhythmia is mediated through a supraventricular action to elevate sinus rate above that of the dominant ventricular focus and thus allow a return to dominance of the sinus node.     

Delayed exacerbation of acute myocardial ischemia/reperfusion-induced arrhythmia by tracheal instillation of diesel exhaust particles

For understanding the relationship between the increased incidence of sudden cardiac death and air pollution, we examined the effects of intratracheal instillation of diesel exhaust particles (DEP) on acute myocardial ischemia/reperfusion-induced arrhythmia in rats. The animals received 1 mg DEP 24-48 h before the ischemia/reperfusion (DEP-pretreated group, DEP-PRE), and were subjected to 3 successive brief ischemia/reperfusion (3 min ischemia followed by 5 min reperfusion) procedures. These were to make the animals tolerant to ischemia/reperfusion-related myocardial deterioration. Thereafter the animals were subjected to a 10-min ischemia followed by a 30-min reperfusion. In the experiments, an increased mortality was observed in the DEP-PRE group compared to the vehicle (0.05% Tween 80-PBS)-treated group. Forty-six percent of the animals in DEP-PRE died during the first 3-min reperfusion period. The animals of other groups were intratracheally instilled with DEP at the beginning of ischemia/reperfusion experiment, or were pretreated with polyethylene glycol-conjugated superoxide dismutase (1000 IU kg(-1), iv). In these animals, incidences of both arrhythmia and mortality were similar to those in the animals treated with the vehicle. In experiments to investigate the effects of DEP on the biochemical and hematological parameters, neutrophil count was elevated by a higher dose (5 mg) of DEP at 24 h after the intratracheal instillation, and oxygen radical production, which was induced by 12-O-tetradecanoylphorbol 13-acetate, was enhanced at 72 h. These results indicate that intratracheal DEP instillation exacerbates short-period ischemia/reperfusion-induced arrhythmia. Delivery and activation of peripheral neutrophils and oxygen radicals produced in neutrophils might participate in this exacerbation. This is the first article that demonstrates the arrhythmogenicity of DEP using intratracheal instillation in rats.     

Delayed Exacerbation of Acute Myocardial Ischemia/Reperfusion-Induced Arrhythmia by Tracheal Instillation of Diesel Exhaust Particles

For understanding the relationship between the increased incidence of sudden cardiac death and air pollution, we examined the effects of intratracheal instillation of diesel exhaust particles (DEP) on acute myocardial ischemia/reperfusion-induced arrhythmia in rats. The animals received 1 mg DEP 24–48 h before the ischemia/reperfusion (DEP-pretreated group, DEP-PRE), and were subjected to 3 successive brief ischemia/reperfusion (3 min ischemia followed by 5 min reperfusion) procedures. These were to make the animals tolerant to ischemia/reperfusion-related myocardial deterioration. Thereafter the animals were subjected to a 10-min ischemia followed by a 30-min reperfusion. In the experiments, an increased mortality was observed in the DEP-PRE group compared to the vehicle (0.05% Tween 80–PBS)-treated group. Forty-six percent of the animals in DEP-PRE died during the first 3-min reperfusion period. The animals of other groups were intratracheally instilled with DEP at the beginning of ischemia/reperfusion experiment, or were pretreated with polyethylene glycol-conjugated superoxide dismutase (1000 IU kg^?1, iv). In these animals, incidences of both arrhythmia and mortality were similar to those in the animals treated with the vehicle. In experiments to investigate the effects of DEP on the biochemical and hematological parameters, neutrophil count was elevated by a higher dose (5 mg) of DEP at 24 h after the intratracheal instillation, and oxygen radical production, which was induced by 12-O-tetradecanoylphorbol 13-acetate, was enhanced at 72 h. These results indicate that intratracheal DEP instillation exacerbates short-period ischemia/reperfusion-induced arrhythmia. Delivery and activation of peripheral neutrophils and oxygen radicals produced in neutrophils might participate in this exacerbation. This is the first article that demonstrates the arrhythmogenicity of DEP using intratracheal instillation in rats.