Piper H M, Hütter J F, Spieckermann P G
Arzneimittelforschung. 1985;35(10):1495-8.
Calcium-tolerant ventricular myocytes from adult rats were electrically stimulated. The maximal contraction frequency (fm) was determined at different temperatures. In drug-free Tyrode solution, fm follows the Arrhenius equation from 7 to 39.5 degrees C. However, all investigated calcium antagonist drugs (verapamil, nifedipine, diltiazem, fendiline) introduce a discontinuity between 27 and 30 degrees C into the Arrhenius plots of fm. Above this transition temperature calcium antagonists lower fm more pronouncedly than below. Below, 10- or 100 fold higher concentrations are needed for the same relative effect as at 37 degrees C. It is argued that these findings might be important in cardiac surgery when calcium antagonists are used for cardioplegia at deep hypothermia.
对成年大鼠耐钙的心室肌细胞进行电刺激。在不同温度下测定最大收缩频率（fm）。在无药物的台氏液中，从7至39.5摄氏度，fm遵循阿伦尼乌斯方程。然而，所有研究的钙拮抗剂药物（维拉帕米、硝苯地平、地尔硫卓、芬地林）在27至30摄氏度之间使fm的阿伦尼乌斯图出现不连续。高于此转变温度时，钙拮抗剂降低fm的程度比低于该温度时更明显。在低于该温度时，要产生与37摄氏度时相同的相对效应，所需浓度要高10倍或100倍。有人认为，当在深低温时使用钙拮抗剂进行心脏停搏液灌注时，这些发现可能在心脏手术中具有重要意义。
