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目的 本文旨在研究汉防已甲素对豚鼠及狗的心肌动作电位 (AP)、收缩力及肌浆网钙吸收的作用。方法 用玻璃微电极的方法 ,研究用药后心肌细胞AP、dV/dt、峰张力 (PT)及dT/dt等指标的改变 ,并用生化方法估价用药后心肌肌浆网钙吸收率及无机磷释放等指标的变化。结果 汉防已甲素起着浓度依赖性和频率依赖性负性变力性作用 ,且缩短了动作电位时程。汉防已甲素抑制心肌dT(E) /dt和dT(L) /dt,也抑制了心肌张力 ,并降低了慢动作电位的dV/dt和幅度 ,这些暗示汉防已甲素可阻止慢钙通道。另外 ,与Thapsigargin(一种特异性肌浆网Ca2 + ATP酶抑制剂 )进行了比较 ,汉防已甲素较之更为明显地抑制了心肌的收缩。结论 汉防已甲素是一种植物性广谱钙离子拮抗剂。它不仅阻止电压操纵的钙通道 (象其它作者所报导的那样 ) ,而且在影响Ca2 + ATP酶及肌浆网钙释放通道方面也起着重要的作用。我们的资料提示钙通道对心肌收缩似乎比肌浆网更为关键。
Objective This study aimed to study the role of hantylin on myocardial action potential (AP), contractility and sarcoplasmic reticulum calcium uptake in guinea pigs and dogs. Methods The changes of AP, dV / dt, peak tension (PT) and dT / dt of cardiomyocytes were studied by glass microelectrode method. The calcium absorption rate and inorganic phosphorus release Other indicators of change. Results Hanfang A played a concentration-dependent and frequency-dependent negative-acting effect, and shortened the action potential duration. Tetrandrine inhibited dT (E) / dt and dT (L) / dt in myocardium, and also inhibited cardiac tension and decreased dV / dt and amplitude of slow-acting potentials, suggesting that trastuzumab may slow down Calcium channel. In addition, compared with Thapsigargin, a specific sarcoplasmic reticulum Ca 2+ -ATPase inhibitor, hantafine inhibits myocardial contractility more significantly. Conclusion Han Fang Tian Su is a plant broad-spectrum calcium antagonist. It not only blocks voltage-manipulated calcium channels (as reported by other authors), but also plays an important role in affecting Ca2 + ATPase and sarcoplasmic reticulum calcium release channels. Our data suggest that calcium channels appear to be more critical to myocardial contractions than sarcoplasmic reticulum.