Studies on alkaligenesis in tissues I. Ammonia production in the nerve fiber during excitations
Studies on alkaligenesis in tissues I. Ammonia production in the nerve fiber during excitations
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DOI：
10.1152/ajplegacy.1922.60.3.519
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发表时间：
1922-05-01
影响因子：
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通讯作者：
Tashiro, S
中科院分区：
文献类型：
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作者：
Tashiro, S
鉴于这一经验，并考虑到目前市场上容易获得用于测定 H+ 浓度的标准指示管，作者预计有人会报告类似的结果，即伴随刺激而增加的新陈代谢无法通过直接指示剂方法检测到。因此，看到罗格斯学院的 AR Moore 的一篇文章 (2) 报道了这样的负面结果也就不足为奇了；重新发现早期工人所取得的负面结果应归功于他。然而，令人惊讶的是，他通过说“神经冲动不依赖于导致二氧化碳产生的输出”来驳回这个问题。然而，目前的通讯并不是要表明是否应该使用指示剂方法来估计神经纤维中的 CO*，也不是要考虑足以解释为什么使用指示剂和我们原始的 CO2 方法获得矛盾结果的所有因素 (3)。首先，要证明神经纤维在二氧化碳产生量增加的同时，会释放出一种碱性物质，而这种物质很可能就是氨；其次，考虑不同条件下神经的烦躁与氨形成之间的关系。实验：第一部分。初步考虑。如果将青蛙的坐骨神经放入林格氏溶液中，使其呈微碱性并用任何弱酸性指示剂（如酚酞）着色，液体迟早会发生酸性反应。因此，如果我们假设在单独的过程中完全无法检测到氨和 CO* 的增加，我们应该预期刺激是由于氨产生的最大量不能大于中和 10 mgm 的 8.7 X 克 CO2 所需的量。使用酚酞作为指示剂在 10 分钟呼吸过程中的神经释放量，因为对于相同的单位，在普通室温下，静止神经释放 5.5 X 10B7 克二氧化碳，激活神经释放 14.2 X low7 克二氧化碳，当然前提是我们之前对二氧化碳的估计是正确的。理论上，34 克 NH3 应中和 44 克 CO2，需要 34 和 8.7 X low7 克 X z= 6.7 X 10W7 克 NH3 来完全中和激发过程中产生的增加的 CO2 量。然而，由于KHAOH比HzCO 3 电离度更高，因此在存在8.7 X 10a克Cog的情况下，远少于6.7 X 10m7克的NH 3 量可能能够维持一定水平的H+浓度，这是
In view of this experience and considering the easy availability of standard indicator tubes now on the market for determination of the H+ concentration, the author expected some one to report similar results, namely, that the increased metabolism accompanying stimulation cannot be detected by a direct indicator method. It is not surprising, therefore, to see an article (2) by AR Moore of Rutgers College in which such a negative result is reported; and to him all the credit for this rediscovery of the negative result obtained by very early workers should be given. It is, however, surprising indeed to see him dismiss this problem by saying that” The nerve impulse dues not depend uport~ owsses leading to the production of carbon dioxide.” The present communication is, however, not to show whether or not an indicator method should be used for estimation of CO* in the nerve fiber, nor to consider all factors which are sufficient to explain why contradictory results were obtained with the indicator and our original CO2 methods (3). It is, first, to prove that the nerve fiber gives off a basic substance simultaneously with an increased production of carbon dioxide and that this substance is most probably ammonia; and second, to consider the relationship between irritability and ammonia formation in the nerve under various conditions. EXPERIMENTAL: Part I. Preliminary consideration. If the sciatic nerve of a frog is placed in Ringer’s solution, made slightly alkaline and colored with any weak acid indicator like phenolphthalein, sooner or later the fluid gives an acid reaction. If, therefore, we assume that the failure entirely to to detect ammonia the increase of CO* during the alone, we should expect that the stimulation is due maximum amount of ammonia production cannot be greater than that necessary to neutralize 8.7 X lo-’grams of CO2 for 10 mgm. of the nerve during 10 minutes of respiration using phenolphthalein as an indicator, since for the same units, a resting nerve gives off 5.5 X 10B7 grams and an activated nerve 14.2 X low7 grams CO2 at ordinary room temperture, provided of course our previous estimation of CO2 is correct. Theoretically, 34 grams of NH3 should neutralize 44 grams of COZ, 34 and 8.7 X low7 grams X z= 6.7 X 10W7 grams of NH3 should be required to completely neutralize just the amount of increased CO2 produced during excitation. However, since KHAOH is more highly ionized than HzC03, the probability is that far less an amount of NH3 than 6.7 X 10m7 grams will be able to maintain a definite level of H+ concentration in presence of 8.7 X lOa grams of Cog, which is the