Bledsoe S W, Mines A H
J Appl Physiol. 1975 Dec;39(6):1012-6. doi: 10.1152/jappl.1975.39.6.1012.
Keeping the arterial pH at 7.4 and PaCO2 at 40 mmHg in eight anesthetized dogs, we acutely raised plasma potassium concentration from 3.4 to 8.2 meq/1, then allowed it to decay back to control levels. The cerebrospinal fluid (CSF)-blood electrical potential difference (pd) increased 13.2 mV per 10-fold increase in plasma [K+]. Again keeping arterial pH at 7.4 and PaCO2 at 40 mmHg, we elevated plasma [K+] in four dogs from 3.3 to 8.0 meq/1 and maintained this level for 6 h. We found 1) that the PD increased from a control value of +1.3 to +8.9mV, showing no tendency to decay over the 6 h; and 2) that the change in PD did not affect the distribution of Na+, K+, H+, Cl-, or HCO3- between blood and CSF over the 6 h. These results suggest that under these conditions the PD between CSF and blood may play no effective role in determining the distributions of these charged species by 6 h. These results are contrasted with recent findings which suggest that H+ and HCO3- are distributed according to passive forces between CSF and blood.
在八只麻醉犬中将动脉血pH维持在7.4，动脉血二氧化碳分压（PaCO2）维持在40 mmHg的情况下，我们将血浆钾浓度从3.4毫当量/升急剧提高到8.2毫当量/升，然后让其回落至对照水平。血浆[K+]每增加10倍，脑脊液（CSF）-血液电势差（pd）增加13.2毫伏。在另外四只犬中，同样将动脉血pH维持在7.4，动脉血二氧化碳分压维持在40 mmHg，我们将血浆[K+]从3.3毫当量/升提高到8.0毫当量/升，并维持该水平6小时。我们发现：1）电势差从对照值+1.3毫伏增加到+8.9毫伏，在6小时内无衰减趋势；2）在6小时内，电势差的变化未影响血液与脑脊液之间Na+、K+、H+、Cl-或HCO3-的分布。这些结果表明，在这些条件下，6小时内脑脊液与血液之间的电势差在决定这些带电物质的分布方面可能未起到有效作用。这些结果与最近的研究结果形成对比，后者表明H+和HCO3-是根据脑脊液与血液之间的被动力量进行分布的。
