Ellory J C, Wolowyk M W
University Laboratory of Physiology, Oxford, England.
Can J Physiol Pharmacol. 1991 May;69(5):588-91. doi: 10.1139/y91-086.
Tracer uptake studies identified the major routes for K+ transport in hagfish red cells, resolving them into ouabain-sensitive, loop diuretic-sensitive, and residual components. The K1/2 values for ouabain, bumetanide, and furosemide were 10(-5), 6 x 10(-7), and 5 x 10(-6) M, respectively. The properties of the Na-K-Cl co-transporter were investigated further by varying K+, Na+, and Cl- concentrations. The measured K1/2 values were similar to those for human red cells. Finally, the stoichiometry of Na:K:Cl uptake was determined, giving 1:1 for K+:Cl-; in contrast, no significant Na+ flux could be measured, although Na+ content must be present for measurable bumetanide-dependent K+ or Cl- flux to occur. The Na-K-Cl transport therefore shows Na(+)-dependent KCl co-transport or partial flux of the system.
示踪剂摄取研究确定了盲鳗红细胞中钾离子运输的主要途径，将其分为对哇巴因敏感、对襻利尿剂敏感和残余部分。哇巴因、布美他尼和呋塞米的半最大效应浓度（K1/2）值分别为10^(-5)、6×10^(-7)和5×10^(-6) M。通过改变钾离子、钠离子和氯离子浓度，进一步研究了钠-钾-氯协同转运体的特性。测得的K1/2值与人类红细胞的相似。最后，确定了钠：钾：氯摄取的化学计量比，钾离子与氯离子为1:1；相比之下，虽然为了使可测量的布美他尼依赖性钾离子或氯离子通量发生必须存在钠离子，但无法测量到显著的钠离子通量。因此，钠-钾-氯转运显示出钠依赖性氯化钾协同转运或该系统的部分通量。
