1. Removal of the external K ions depolarized the membrane of the guinea-pig taenia coli by about 5 mV, and increased the frequency of the spontaneous spike activity. After about 20 min in K-free solution, the frequency gradually decreased and spontaneous activity stopped after about 60 min.2. Readmission of K produced a transient hyperpolarization by 10-15 mV for 10-20 min, and lowered the excitability. The membrane resistance decreased during the hyperpolarization. When the external K concentration was returned to normal before the spontaneous activity had disappeared in K-free solution, there was a complete suppression of the spontaneous electrical and mechanical activities, accompanied by hyperpolarization of the membrane. The duration of this suppression of electrical and mechanical activities depended on the exposure time to K-free solution, the recovery being delayed by longer exposure.3. The effects of removing external K were essentially the same in the presence of tetrodotoxin (10-7 g/ml.), of atropine (10-6 g/ml.), and also in low Cl (2-7 mM).4. The effects of ouabain (10-6 g/ml.) were similar to those of zero K but appeared more slowly. After treatment with ouabain, the membrane was hyperpolarized by removing the external K and there was no hyperpolarization nor suppression of the mechanical activity on readmission of external K.5. Rb substitution for K produced little effect and addition of 5·9 mM-Rb after K-removal produced a typical suppression of activity as the readmission of K. When K was replaced with an equimolar concentration of Cs, the effects were similar to those produced by K-free solution.6. The pattern of the response to a change in the external K concentration was different below 23° C. The spontaneous activity was suppressed by removal of K, and increased by returning the external K.7. It is concluded that, in the taenia, the membrane potential can be modified by an electrogenic pump, the activity of which is inhibited by removing K, by ouabain, and by lowering the temperature to about 23° C. During the recovery from the exposure to K-free solution or to ouabain, the pump activity is potentiated, causing hyperpolarization of the membrane by 10-20 mV. Rb can, Cs cannot, replace K in activating the pump at the same concentration as K.
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机译：1.去除外部K离子使豚鼠带状虫的膜去极化约5 mV，并增加了自发性刺突活动的频率。在无钾溶液中约20分钟后，频率逐渐降低，约60分钟后自发活动停止2。钾的再吸收在10-20分钟内产生了10-15 mV的瞬时超极化，并降低了兴奋性。在超极化过程中，膜电阻降低。在无钾溶液中自发活性消失之前，当外部钾离子浓度恢复到正常水平时，自发的电气和机械活性被完全抑制，伴随着膜的超极化。抑制电气和机械活动的持续时间取决于无钾溶液的暴露时间，更长的暴露时间会延迟恢复。3。在存在河豚毒素（10 -7 g / ml。）和阿托品（10 -6 g / ml。）的情况下，去除外部钾的作用基本相同。 ，以及低Cl（2-7 mM）。4。哇巴因（10 -6 g / ml。）的作用类似于零K的作用，但出现较慢。用哇巴因处理后，通过去除外部K使膜超极化，并且在重新吸收外部K.5时没有超极化也没有抑制机械活性。用Rb替代K几乎没有效果，并且在去除K后添加5·9 mM-Rb对K的再吸收具有典型的抑制活性。当用等摩尔浓度的Cs替代K时，其效果与所产生的相似通过无K解决方案6。在低于23°C时，对外部K浓度变化的响应方式有所不同。通过去除K抑制了自发活性，通过返回外部K.7增强了自发活性。结论是，在ta带中，膜电位可以通过电泵改变，其活性可通过去除K，哇巴因并将温度降低至约23°C来抑制。对于无钾溶液或哇巴因，泵浦活性增强，导致膜超极化10-20 mV。 Rb可以，Cs不能以与K相同的浓度替换K来激活泵。
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