Takács I E, Mészáros J, Szegi J
Acta Physiol Hung. 1984;64(2):163-71.
The effect of hypothyroid state on the transmembrane potential was studied in isolated cardiac ventricular trabeculae of rats. Hypothyroid state was induced by methimazole treatment or thyroidectomy and checked by determining serum thyroxine level. Hypothyroidism decreased the maximum rate of depolarization (Vmax) and the resting potential, increased the overshoot and the duration of action potential at 20, 50 and 90% repolarization. These changes were more pronounced after methimazole treatment than after thyroidectomy. The results strongly suggest that in hypothyroidism the significant alterations in the voltage-time course of the transmembrane action potential influencing Ca2+-movement across the sarcolemma may have an indirect role in the decreased myocardial contractility. On the other hand, methimazole has an aspecific cardiac effect which may modify the cardiac effect of hypothyroidism induced by the drug.
在大鼠离体心脏心室小梁中研究了甲状腺功能减退状态对跨膜电位的影响。通过甲巯咪唑治疗或甲状腺切除术诱导甲状腺功能减退状态，并通过测定血清甲状腺素水平进行检查。甲状腺功能减退降低了最大去极化速率（Vmax）和静息电位，增加了超射以及动作电位在复极化20%、50%和90%时的持续时间。这些变化在甲巯咪唑治疗后比甲状腺切除术后更明显。结果强烈表明，在甲状腺功能减退时，跨膜动作电位电压 - 时间过程中的显著改变影响Ca2 +跨肌膜的移动，可能在心肌收缩力降低中起间接作用。另一方面，甲巯咪唑具有非特异性心脏效应，这可能会改变该药物诱导的甲状腺功能减退的心脏效应。
