Holubarsch C, Hasenfuss G, Just H, Blanchard E, Mulieri L A, Alpert N R
Department of Internal Medicine, University of Freiburg, F.R.G.
J Cardiovasc Pharmacol. 1989;14 Suppl 2:S13-7.
Using antimony-bismuth myothermal equipment, we measured simultaneously the initial heat liberated from and the stress-time integral developed by guinea pig papillary muscles before and after application of UD-CG 115 BS (200 microM) at an experimental temperature of 21 degrees C. By means of the shortening method, the initial heat was subdivided into the activation heat, which is associated with the calcium turnover, and the tension-dependent heat, which represents the ATP splitting by contractile proteins. The activation heat increased slightly but not significantly from 0.24 +/- 0.05 to 0.34 +/- 0.09 mcal/g. The increase in the tension-dependent heat (from 0.23 +/- 0.07 to 0.49 +/- 0.22 mcal/g) was directly proportional to the increase in the developed stress-time integral (from 0.95 +/- 0.24 to 2.37 +/- 0.76 g.s/mm2). The data indicate that the economy of force generation by contractile proteins is unchanged by UD-CG 115 BS, whereas the activation heat may be slightly increased by this compound. A comparison of UD-CG 115 BS with other substances like isoproterenol or classic phosphodiesterase inhibitors reveals that UD-CG 115 BS increases myocardial force in a more economical way that may have clinical implications. The mode of action of this compound is attributed to its calcium-sensitizing effect on the contractile proteins.
使用锑铋温差热设备，我们在21摄氏度的实验温度下，于应用UD - CG 115 BS（200微摩尔）前后，同时测量了豚鼠乳头肌释放的初始热量以及产生的应力 - 时间积分。通过缩短法，将初始热量细分为与钙周转相关的活化热以及代表收缩蛋白ATP分解的张力依赖性热。活化热从0.24±0.05微卡/克略有增加至0.34±0.09微卡/克，但无显著差异。张力依赖性热的增加（从0.23±0.07微卡/克至0.49±0.22微卡/克）与产生的应力 - 时间积分的增加（从0.95±0.24克·秒/平方毫米至2.37±0.76克·秒/平方毫米）成正比。数据表明，UD - CG 115 BS不会改变收缩蛋白产生力的经济性，而该化合物可能会使活化热略有增加。将UD - CG 115 BS与异丙肾上腺素或经典磷酸二酯酶抑制剂等其他物质进行比较发现，UD - CG 115 BS以一种更经济的方式增加心肌力，这可能具有临床意义。该化合物的作用方式归因于其对收缩蛋白的钙敏化作用。
