McDonald T F, DeHaan R L
J Gen Physiol. 1973 Jan;61(1):89-109. doi: 10.1085/jgp.61.1.89.
Intracellular concentrations of sodium and potassium as well as resting potentials and overshoots have been determined in heart tissue from chick embryos aged 2-18 days. Intracellular potassium declined from 167 mM at day 2 to 117-119 mM at days 14-18. Intracellular sodium remained nearly constant at 30-35 mM during the same period. The mean resting potential increased from -61.8 mV at day 3 to about -80 mV at days 14-18. The mean overshoot during the same period increased from 12 to 30 mV. P(Na)/P(K) calculated from the ion data and resting potentials declined from 0.08 at day 3 to 0.01 at days 14-18. Thus, the development of embryonic chick heart during days 2-14 is characterized by a declining intracellular potassium concentration and an increasing resting potential and overshoot. Heart cells from 7- to 8-day embryos, cultured either in monolayer or reassociated into aggregates, were compared with intact tissue of the same age. The intracellular concentrations of sodium and potassium were similar in the three preparations and cultured cells responded to incubation in low potassium medium or treatment with ouabain in a manner similar to that of intact tissue. Resting potentials and overshoots were also similar in the three preparations.
已测定了2至18日龄鸡胚心脏组织中的细胞内钠和钾浓度以及静息电位和超射值。细胞内钾浓度从第2天的167 mM降至第14至18天的117 - 119 mM。同期细胞内钠浓度在30 - 35 mM基本保持恒定。平均静息电位从第3天的-61.8 mV增加到第14至18天的约-80 mV。同期平均超射值从12 mV增加到30 mV。根据离子数据和静息电位计算得出的P(Na)/P(K)从第3天的0.08降至第14至18天的0.01。因此，鸡胚心脏在第2至14天的发育特征是细胞内钾浓度下降，静息电位和超射值增加。将7至8日龄胚胎的心脏细胞单层培养或重新聚集成团块培养，并与相同年龄的完整组织进行比较。三种制剂中细胞内钠和钾的浓度相似，培养细胞在低钾培养基中孵育或用哇巴因处理时的反应方式与完整组织相似。三种制剂中的静息电位和超射值也相似。
