Dagher G, Brossard M, Feray J C, Garay R P
Life Sci. 1985 Jul 22;37(3):243-53. doi: 10.1016/0024-3205(85)90650-2.
Different Na transport pathways were studied in the erythrocytes of 10 normotensive subjects who received 240 meq/day of Na in excess of their usual diet. In most of these subjects the maximal rate (Vmax) of the Na,K pump and the Na,K-cotransport system was markedly decreased on the first day of the diet. In some of these subjects, excess Na intake induced an increase in the apparent affinity for internal Na for the Na,K pump and the Na,K-cotransport system. The decrease in the Na,K pump fluxes was not concomitant to that of the co-transport system and not accompanied with an increase in blood pressure or cation concentration in the plasma. Interestingly, the apparent affinity for internal Li of the Li-Na exchange was markedly increased without alteration of the Vmax. The passive permeability for Na and the cellular Na content were not altered by excess Na intake. Ouabain and bumetanide at low concentrations respectively induced an increase in the apparent affinity for internal Na of the Na,K pump and the Na,K- cotransport system. These results are similar to those observed after excess Na intake. These later agree with the hypothesis that Na homeostasis regulates some endogenous factors with ouabain-like and furosemide-like properties that might contribute to the regulation of cellular Na handling.
在10名血压正常的受试者的红细胞中研究了不同的钠转运途径，这些受试者每天摄入比其平常饮食多240毫当量的钠。在这些受试者中的大多数，钠钾泵和钠钾共转运系统的最大速率（Vmax）在饮食的第一天显著降低。在其中一些受试者中，过量的钠摄入导致钠钾泵和钠钾共转运系统对细胞内钠的表观亲和力增加。钠钾泵通量的降低与共转运系统的降低不同步，且不伴有血压升高或血浆中阳离子浓度增加。有趣的是，锂钠交换对细胞内锂的表观亲和力显著增加，而Vmax未改变。过量的钠摄入未改变钠的被动通透性和细胞内钠含量。低浓度的哇巴因和布美他尼分别导致钠钾泵和钠钾共转运系统对细胞内钠的表观亲和力增加。这些结果与过量钠摄入后观察到的结果相似。这些结果与以下假设一致，即钠稳态调节一些具有哇巴因样和速尿样特性的内源性因子，这些因子可能有助于调节细胞对钠的处理。
