Brand S C, Whittam R
J Physiol. 1984 Mar;348:301-6. doi: 10.1113/jphysiol.1984.sp015111.
A study has been made of Na movements in human red blood cells in order to test their sensitivity to inhibition by furosemide or bumetanide. Net changes as well as influx and efflux were measured. Unidirectional Na influx and efflux values confirmed previous evidence for components of both these fluxes sensitive to inhibition by furosemide or bumetanide. The difference between furosemide-sensitive unidirectional influx and efflux was determined at [Na]o 140 mM and shown to be non-significant, even when [Na]i was raised to about 45 mumol ml cells-1. No evidence was found for an influence of furosemide on net movements of Na in cells of either slightly elevated or physiological [Na]i incubated in a 140 mM-Na medium over 4 h. Incubation of cells, under similar conditions, for 12 h did not reveal a bumetanide-sensitive net Na movement. The results suggest that cells with normal or slightly elevated [Na]i, incubated in media of physiological Na concentration, do not possess a mechanism sensitive to inhibition by the loop diuretics that operates to regulate cell Na.
为了测试速尿或布美他尼对其抑制的敏感性，对人类红细胞中的钠运动进行了一项研究。测量了净变化以及流入和流出。单向钠流入和流出值证实了先前关于这两种通量的成分对速尿或布美他尼抑制敏感的证据。在[Na]o 140 mM时测定了速尿敏感的单向流入和流出之间的差异，结果表明即使[Na]i升高至约45 μmol/ml细胞-1，该差异也不显著。在140 mM-Na培养基中孵育4小时，未发现速尿对轻度升高或生理[Na]i的细胞中钠的净运动有影响。在类似条件下将细胞孵育12小时，未发现布美他尼敏感的钠净运动。结果表明，在生理钠浓度的培养基中孵育的[Na]i正常或轻度升高的细胞，不具有对袢利尿剂抑制敏感的调节细胞钠的机制。
