Orsenigo M N, Tosco M, Esposito G, Faelli A
Arch Int Physiol Biochim. 1987 Mar;95(1):57-66. doi: 10.3109/13813458709075025.
Basolateral membranes purified from rat jejunal enterocytes and enriched 14 times in (Na, K)-ATPase, are present as unsealed and right side out (RSO) or inside out (IO) vesicles in the ratio 2:2:1, as determined by detergent activation of ATPase activity. Entrance of 1 mM Na into basolateral membrane vesicles was measured in the presence and in the absence of 5 mM ATP by a rapid filtration technique, under different experimental conditions. Carrier-mediated Na transport across the basolateral membrane can be trans-stimulated and cis-inhibited by K and further stimulated by ATP (activation of the Na pump). The ATP effect can be suppressed by vanadate and strophanthidin and enhanced by bleomycin (19% increase), which positively also acts on (Na, K)-ATPase activity (16% increase). In addition to the Na pump this study demonstrates the existence of a carrier-mediated Na transport trans-stimulated by K. There appears to be no cotransport of Na-K.
从大鼠空肠肠上皮细胞纯化得到的基底外侧膜，其（钠，钾）-ATP酶富集了14倍，以未封闭的、外翻（RSO）或内翻（IO）囊泡的形式存在，比例为2:2:1，这是通过对ATP酶活性的去污剂激活来确定的。在不同实验条件下，通过快速过滤技术，在存在和不存在5 mM ATP的情况下，测量1 mM钠进入基底外侧膜囊泡的情况。载体介导的钠跨基底外侧膜的转运可被钾反刺激和顺抑制，并被ATP进一步刺激（钠泵激活）。钒酸盐和毒毛花苷可抑制ATP的作用，博来霉素可增强其作用（增加19%），博来霉素对（钠，钾）-ATP酶活性也有正向作用（增加16%）。除了钠泵，本研究还证明了存在一种由钾反刺激的载体介导的钠转运。似乎不存在钠-钾共转运。
