Tosco M, Orsenigo M N, Esposito G, Faelli A
Dipartimento di Fisiologia e Biochimica Generali, Università di Milano, Italy.
Proc Soc Exp Biol Med. 1988 Jun;188(2):122-7. doi: 10.3181/00379727-188-42716.
The jejunal tract of rat intestine, everted and incubated in vitro at 28 degrees C for 2 hr in Krebs-Ringer bicarbonate solution, was used to test the existence of a ouabain-insensitive sodium pump. Cell water, Na, and K together with Na, fluid, K, and lactate transported into the serosal compartment were determined and, under control conditions, the tested parameters were found constant in time. By blocking the Na-K pump with 20 mM ouabain in the serosal compartment, the enterocyte lost K and gained Na, but the cell volume did not vary. Moreover, the transport of Na, fluid, and lactate, although lower, was constant for 2 hr. When ethacrynate was added or when the ATP supply was blocked by adding 2,4-dinitrophenol plus iodoacetate, the cell swelled and the transport of Na and fluid stopped. These results are interpreted as suggesting the existence of a ouabain-insensitive Na pump, in addition to the well-known Na-K pump.
将大鼠小肠的空肠段翻转，于28℃在Krebs - Ringer碳酸氢盐溶液中体外孵育2小时，用于测试哇巴因不敏感钠泵的存在。测定了细胞内的水、钠和钾以及转运至浆膜腔的钠、液体、钾和乳酸，在对照条件下，所测参数在一段时间内保持恒定。通过在浆膜腔中用20 mM哇巴因阻断钠钾泵，肠上皮细胞丢失钾并摄取钠，但细胞体积未发生变化。此外，钠、液体和乳酸的转运虽然降低，但在2小时内保持恒定。当加入依他尼酸或通过添加2,4 - 二硝基苯酚和碘乙酸阻断ATP供应时，细胞肿胀，钠和液体的转运停止。这些结果被解释为表明除了众所周知的钠钾泵外，还存在哇巴因不敏感钠泵。
