Hasegawa J, Matsumoto T, Takami T, Fujimoto Y, Kotake H, Mashiba H
Department of Internal Medicine, Tottori University School of Medicine, Yonago, Japan.
Magnesium. 1989;8(2):94-9.
The effect of magnesium ion on the abnormal pacemaker activity of guinea pig ventricular muscle cells depolarized by 27 mM K+ was studied. Isoproterenol produced a small depolarization in the resting membrane and elicited automatic repetitive action potentials at higher concentrations in the presence of 0.2 mM Ba2+. This model was used to assess the antiarrhythmic effect of magnesium ion on cardiac muscle cells. Isoproterenol concentrations needed for depolarization alone or for depolarization plus automatic activity were taken as a basis for evaluation. The responsiveness of muscle cells to isoproterenol was suppressed significantly by increasing the magnesium concentration. It is concluded that magnesium ion may have an antiarrhythmic effect on partially depolarized cardiac muscle cells.
研究了镁离子对由27 mM钾离子所致去极化的豚鼠心室肌细胞异常起搏活动的影响。异丙肾上腺素在静息膜电位上产生小的去极化，并在存在0.2 mM钡离子的情况下，在较高浓度时引发自动重复动作电位。该模型用于评估镁离子对心肌细胞的抗心律失常作用。仅去极化或去极化加自动活动所需的异丙肾上腺素浓度作为评估依据。通过增加镁离子浓度，肌肉细胞对异丙肾上腺素的反应性被显著抑制。得出的结论是，镁离子可能对部分去极化的心肌细胞具有抗心律失常作用。
