夹竹桃对蛙心收缩力的影响及其机制探讨
【摘要】 目的 探讨不同剂量的夹竹桃和毒K（毒毛花苷(甙)K）对蟾蜍心脏的作用及其相关机制。方法 采用离体蟾蜍心脏，用含戊巴比妥钠（2mmol/L,1ml）的任氏液造成蟾蜍心衰模型（心肌收缩力降低一半时为心衰），经张力换能器、BL-410智能生物信号显示与处理系统记录心肌的收缩活动的曲线。5min作为对照组，然后观察药物对其作用，2min后曲线变化，并与对照组比较。结果 灌流不同浓度的夹竹桃液后，2%的夹竹桃液(0.2ml)使心肌在2min内收缩频率迅速加强，幅度也达到最大，10min后心肌收缩频率和幅度再缓慢减弱恢复至对照组水平。而2%(0.2ml)的毒K连续观察2min，5min，8min心肌收缩频率没有变化。结论 一定浓度的夹竹桃液对心肌的收缩力和幅度都有所加强，而同一浓度同一时间的毒K心肌收缩率和幅度呈一直线，2%的夹竹桃液增加心肌收缩率和幅度作用较强，时间较短，而毒K时间长，剂量大。二者比较差异显著。结论 2%的夹竹桃液对心肌的收缩力和幅度都有加强，而毒K治疗量接近中毒量的60%。
【关键词】 医夹竹桃 离体蟾蜍心脏 蟾蜍
【Abstract】 Objective: Finding out the impact and the relevant mechanism of different dosages of oleander and Strophanthin k on the heart of toad; Approach: Forming a heart-failure model making use of Ringer’s solution containing Sodium pentobarbital (2mmol/L, 1ml) with in vitro of the heart of toad (When the myocardial contraction force is decreased by a half, it is called heart failure); the curves of contraction is recorded with a tonotransducer and a BL-410 bio-signal display and processing system. The result after five minutes is taken as a control group and then the impact of drug on it is observed; after 2 minutes the curve is changed and the it is compared with the control group. Results: After feeding different densities of oleander, it is found that the contraction frequency of the myocardial is rapidly intensified and the amplitude is the largest after 2 minutes when 2% (2ml) density of oleander is fed; after ten minutes, the contraction frequency of the myocardial is slowly receded and finally reach the level of that of the control group. While 2% density of Strophanthin k is fed and the continuous observation is found that after 2 minutes, 5 minutes and 8 minutes the frequency of contraction of myocardial is not changed. Conclusion: certain concentration oleander will intensify the frequency and amplitude of myocardial contraction, but when the Strophanthin k of the same concentration and time is fed, the frequency and amplitude of myocardial contraction will become a straight line. 2% concentration oleander will have a stronger impact on the frequency and amplitude of myocardial contraction in a shorter time, while more dosage of Strophanthin k and more time are needed to have the same impact with that of oleander. There is a marked deference between the action of oleander and Strophanthin k. The curative dose of Strophanthin k is about 60% of those of moderately toxic.
【Key words】 Oleander Isolated toad heart Toad
夹竹桃属于强心类中药。味苦、性寒、有毒，归心经。主要功能为强心利尿、祛痰定喘、镇痛、祛瘀。近代临床运用该药治疗心脏病心力衰竭、喘息咳嗽、癫痫、跌打损伤、经闭、斑秃。本品有毒，内服煎汤，剂量为0.3～0.9g。
1 材料与方法
1.1材料
取夹竹桃25g，洗净用纱布擦干，剪碎，置广口瓶内，加70%乙醇100ml，室温浸泡48h，并经常振摇，用棉花过滤，再用70%乙醇适量洗叶片，挤压取滤液，滤液在水浴锅上蒸干，得粗醇浸出液，用适量任氏液溶解浸出物，用滤纸过滤，最后用任氏液加至250ml，既为10%夹竹桃任氏液置冰箱备用。（用时稀释10倍）
1.2 方法
取蟾蜍一只，用探针破坏脑及脊髓，依次切开胸部皮肤和胸骨，剪开心包膜充分暴露心脏，并与左右主动脉下穿两根线，其中一根打松结备结扎用，然后用剪刀在主动脉上作一V型切口，将盛有任氏液的蛙心套管插入主动脉，经主动脉球入心室，此时，蛙心套管液面既随心室搏动而上下移动，扎紧松结，把蛙心套管固定在胶泥上，使心脏提起，用另一根线在静脉窦下方结扎，沿扎线远端剪断左右主动脉及下腔静脉，制成离体蛙心标本，用吸管吸去套管内的血液，加入任氏液冲洗至灌流液无色，并使液面保持恒定，将标本固定在蛙心套管夹住心尖在制备好了的蛙心中加入含戊巴比妥钠（2mmol/L,1ml）的任氏液造成蟾蜍心衰模型（心肌收缩力降低一半时为心衰）并与BL-410系统相连。用计算机生物记录分析系统记正常收缩曲线5min，然后给药连续记录25min观察夹竹桃对离体蛙心收缩幅度，收缩频率的影响。
2 结果
灌流不同浓度的夹竹桃液后，2%的夹竹桃液(0.2ml)使心肌在2min内收缩频率迅速加强，幅度也达到最大，10min后心肌收缩频率和幅度再缓慢减弱恢复至对照组水平。而2%(0.2ml)的毒K连续观察2min，5min，8min心肌收缩频率没有变化。
3 结论
一定浓度的夹竹桃液对心肌的收缩频率和幅度都有所加强，其作用机理该药治疗心力衰竭有一定的作用，而同一浓度同一时间的毒K心肌收缩频率和幅度呈一直线，2%的夹竹桃液增加心肌收缩频率和幅度作用较强，时间较短，而毒K时间长，剂量大，治疗量接近中毒量的60%。
参 考 文 献
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[2] 刘静.夹竹桃中毒的治疗[J].国外药讯，2000，（7）：43.
