Beaver W L, Wasserman K, Whipp B J
J Appl Physiol (1985). 1986 Feb;60(2):472-8. doi: 10.1152/jappl.1986.60.2.472.
The pattern of decrease in arterial bicarbonate concentration ([HCO3-]) during progressive incremental exercise was compared with that of the rise in arterial lactate ([La-]) to determine the degree of buffering of lactic acid by bicarbonate. A mathematical model was derived for the change in [HCO3-] beyond the lactate threshold. This was based on a log-log transformation of the data, a model previously found to provide a very good fit to the [La-]-O2 consumption (VO2) relationship. The results of the analysis of incremental exercise data from 10 subjects show that the decrease in [HCO3-] very nearly matches the increase in [La-]. However, it was found by comparing regression models that the correspondence between [HCO3-] and [La-] could be improved by assuming that the [HCO3-] decrease was delayed until the arterial lactate level had increased by approximately 0.4 meq/l. This result is compatible with the existence of buffering mechanisms in the cell which buffer the initial increase of lactic acid. Beyond this initial buffering, lactic acid appears to be buffered almost entirely by the bicarbonate buffer system.
在递增运动过程中，将动脉血碳酸氢盐浓度（[HCO₃⁻]）的下降模式与动脉血乳酸（[La⁻]）的上升模式进行比较，以确定碳酸氢盐对乳酸的缓冲程度。推导了一个超出乳酸阈值时[HCO₃⁻]变化的数学模型。这是基于对数据进行对数-对数转换，此前发现该模型能很好地拟合[La⁻]-耗氧量（VO₂）关系。对10名受试者递增运动数据的分析结果表明，[HCO₃⁻]的下降几乎与[La⁻]的增加相匹配。然而，通过比较回归模型发现，假设[HCO₃⁻]的下降延迟到动脉血乳酸水平增加约0.4毫当量/升时，[HCO₃⁻]与[La⁻]之间的对应关系会得到改善。这一结果与细胞中存在缓冲机制以缓冲乳酸的初始增加相一致。在这种初始缓冲之后，乳酸似乎几乎完全由碳酸氢盐缓冲系统缓冲。
