Hougen T J, Hopkins B E, Smith T W
Am J Physiol. 1978 Mar;234(3):C59-63. doi: 10.1152/ajpcell.1978.234.3.C59.
The effects of insulin on monovalent cation transport and on Na-K-ATPase activity from intact cells, tissue homogenates, and purified enzyme of the avian salt gland were studied. Monovalent cation active transport, measured by ouabain-inhibitable 86Rb+ uptake, was significantly increased (21.9 +/- 7.3% SE) in tissue slices exposed to insulin (100 mU/ml) for 15 min. A small but significant (12.2 +/- 1.9%) increase in Na-K-ATPase activity was similarly observed after salt gland tissue slices were exposed to insulin. This increase in enzymatic activity did not occur when broken-cell homogenates were exposed to insulin. Purified preparations of Na-K-ATPase showed no insulin enhancement of activity either in the presence of optimal or less than fully activating Na+ and ATP concentrations. Na-K-ATPase activity was the same in detergent-activated homogenates of both control and insulin-treated slices, consistent with insulin activation of existing enzyme sites. These data support the hypothesis that at least part of the increase in monovalent cation active transport produced by insulin is related to enhanced Na-K-ATPase activity and indicate that the latter phenomenon is dependent on some components or properties of the intact cell.
研究了胰岛素对禽盐腺完整细胞、组织匀浆及纯化酶中单价阳离子转运和钠钾ATP酶活性的影响。用哇巴因抑制的⁸⁶Rb⁺摄取来测定单价阳离子主动转运，在暴露于胰岛素（100 mU/ml）15分钟的组织切片中，该转运显著增加（21.9±7.3%标准误）。在盐腺组织切片暴露于胰岛素后，同样观察到钠钾ATP酶活性有小幅但显著（12.2±1.9%）的增加。当破碎细胞匀浆暴露于胰岛素时，酶活性并未增加。纯化的钠钾ATP酶制剂在存在最佳或低于完全激活浓度的Na⁺和ATP时，其活性也未得到胰岛素的增强。对照和胰岛素处理切片的去污剂激活匀浆中的钠钾ATP酶活性相同，这与胰岛素激活现有酶位点一致。这些数据支持这样的假说，即胰岛素产生的单价阳离子主动转运增加至少部分与钠钾ATP酶活性增强有关，并表明后一种现象依赖于完整细胞的某些成分或特性。
