Ventura-Clapier R, Vassort G
J Physiol (Paris). 1980 Nov;76(6):583-9.
The hypodynamic state of frog heart has been investigated from the energetic point of view. The amplitude of tension was enhanced when the oxidative metabolism was stimulated by oxygen and pyruvate. However, a time-dependent tension decrease still occurred with both oxygen and pyruvate. Hypodynamia, although slowed down under these conditions, was accompanied by a decrease in CP rather than in ATP. It is shown that the decrease in CP was due to a leak of creatine out of the cell, consequent to the non-equilibration of the oncotic pressure in the perfusion fluid. Creatine (20 mM) or any plasma expander, prevented the fall in both CP and tension. These results are in agreement with the proposal that the CP/CK/Cr system is the major metabolic intermediate between production and use of energy for contraction and that, besides Ca ions, it participates in the regulation of tension. It is suggested that hypodynamia mostly originates in a decreased Ca utilization due to shortage of energy.
已从能量角度对蛙心的低动力状态进行了研究。当氧气和丙酮酸刺激氧化代谢时，张力幅度会增强。然而，在使用氧气和丙酮酸的情况下，张力仍会随时间下降。低动力状态虽然在这些条件下有所减缓，但伴随着磷酸肌酸（CP）而非三磷酸腺苷（ATP）的减少。结果表明，CP的减少是由于灌注液中胶体渗透压失衡导致肌酸从细胞中泄漏所致。肌酸（20 mM）或任何血浆扩容剂可防止CP和张力的下降。这些结果与以下观点一致：CP/肌酸激酶/肌酸（CK/Cr）系统是能量产生与收缩能量利用之间的主要代谢中间体，并且除钙离子外，它还参与张力调节。有人提出，低动力状态主要源于能量短缺导致的钙离子利用减少。
