Meier C F, Briggs G M, Claycomb W C
Am J Physiol. 1986 May;250(5 Pt 2):H731-5. doi: 10.1152/ajpheart.1986.250.5.H731.
Action and resting potential characteristics of isolated adult rat myocardial cells maintained in culture for 10-28 days are described. Resting potentials averaged -76.3 +/- 2 mV in 5 mM extracellular [K+] ([K+]o). Resting potentials changed by 54.3 mV/decade change in [K+]o for concentrations greater than 5 mM. The average maximum rate of rise of action potential (Vmax) was 117.7 +/- 10 V/s with overshoots of 34.6 +/- 2.5 mV. Action potential durations (APD) to 0 and -40 mV and full repolarization were 21.8 +/- 3.9, 36.3 +/- 6.0, and 206 +/- 16.9 ms respectively. Action potential configurations were qualitatively similar to those previously reported by others for rat myocardial tissue or freshly dissociated cells. Tetrodotoxin (4 micrograms/ml) decreased Vmax to less than 24 V/s and decreased overshoot and APD. Isoproterenol (10(-8) M) decreased APD with slight elevation of the overshoot. Verapamil (10(-5) to 10(-4) M) depressed overshoot and plateau while slowing the final phase of repolarization. Verapamil (10(-4) M) depressed upstroke velocity and blocked excitability. While APDs recorded from these cultured cells are apparently longer than those reported by others for rat myocardial APDs, the values of all other electrophysiological parameters recorded are within the limits previously reported for normal rat myocardial tissue. These data indicate that adult rat myocardial cells maintained in tissue culture for 10-28 days possess electrophysiological properties and responses to pharmacological agents similar to adult rat myocardial tissue or undamaged freshly isolated cells.
本文描述了体外培养10 - 28天的成年大鼠心肌细胞的动作电位和静息电位特征。在5 mM细胞外钾离子浓度（[K⁺]ₒ）条件下，静息电位平均为 -76.3 ± 2 mV。当[K⁺]ₒ浓度大于5 mM时，静息电位随[K⁺]ₒ每十倍变化改变54.3 mV。动作电位的平均最大上升速率（Vmax）为117.7 ± 10 V/s，超射值为34.6 ± 2.5 mV。动作电位至0和 -40 mV以及完全复极化的持续时间（APD）分别为21.8 ± 3.9、36.3 ± 6.0和206 ± 16.9 ms。动作电位形态在质量上与其他人先前报道的大鼠心肌组织或新鲜分离细胞的相似。河豚毒素（4微克/毫升）使Vmax降至小于24 V/s，并降低超射值和APD。异丙肾上腺素（10⁻⁸ M）降低APD，同时使超射值略有升高。维拉帕米（10⁻⁵至10⁻⁴ M）降低超射值和平坦期，同时减慢复极化的最后阶段。维拉帕米（10⁻⁴ M）降低上升速度并阻断兴奋性。虽然从这些培养细胞记录的APD明显长于其他人报道的大鼠心肌APD，但记录的所有其他电生理参数值均在先前报道的正常大鼠心肌组织的范围内。这些数据表明，在组织培养中维持10 - 28天的成年大鼠心肌细胞具有与成年大鼠心肌组织或未受损的新鲜分离细胞相似的电生理特性和对药物的反应。
