Gomes, Pedro, and Patrı́cio Soares-da-Silva. Upregulation of apical NHE3 in renal OK cells overexpressing the rodent 1-subunit of the Na pump. Am J Physiol Regul Integr Comp Physiol 290: R1142–R1150, 2006. First published November 17, 2005; doi:10.1152/ajpregu.00102.2005.— Vectorial Na reabsorption across the proximal tubule is mediated by apical entry of Na , primarily via Na /H exchanger isofo...

In our previous studies, we have demonstrated that the Src-coupled α1 Na/K-ATPase works as a receptor for cardiotonic steroids, such as ouabain, to regulate cellular protein kinase cascades. Here, we explore further the structural determinants of the interaction between the α1 Na/K-ATPase and Src and demonstrate that the Src-coupled α1 Na/K-ATPase allows the cell to decode the transmembrane tra...

The Na,K-ATPase is essential for the contractile function of skeletal muscle, which expresses the α1 and α2 subunit isoforms of Na,K-ATPase. The α2 isozyme is predominant in adult skeletal muscles and makes a greater contribution in working compared with noncontracting muscles. Hindlimb suspension (HS) is a widely used model of muscle disuse that leads to progressive atrophy of postural skeleta...

The depolarization of neurons induced by impairment of Na+,K+-ATPase activity after long-term opiate treatment has been shown to involve the development of opioid dependence. However, the mechanisms underlying changes in Na+,K+-ATPase activity after opioid treatment are unclear. The best-established molecular adaptation to long-term opioid exposure is up-regulation of the cAMP/cAMP-dependent pr...

We studied the cellular membrane enzyme responsible for potassium transport in different Thai populations. We measured plasma and intraerythrocytic concentrations of sodium and potassium, activities of erythrocytic membrane Na, K-activated adenosine triphosphatase (Na, K-ATPase), ouabain-insensitive ATPase, total ATPase and the activity ratio of Na, K-ATPase/total ATPase in 25 healthy blood don...

Vectorial Na(+) reabsorption across the proximal tubule is mediated by apical entry of Na(+), primarily via Na(+)/H(+) exchanger isoform 3 (NHE3), and basolateral extrusion via the Na(+) pump (Na(+)-K(+)-ATPase). We hypothesized that regulation of Na(+) reabsorption should involve not only the activity of the basolateral Na(+)-K(+)-ATPase, but also the apical NHE3, in a concerted manner. To gen...

Several members of the FXYD protein family are tissue-specific regulators of Na,K-ATPase that produce distinct effects on its apparent K(+) and Na(+) affinity. Little is known about the interaction sites between the Na,K-ATPase alpha subunit and FXYD proteins that mediate the efficient association and/or the functional effects of FXYD proteins. In this study, we have analyzed the role of the tr...

Brain excitation increases neuronal Na(+) concentration by 2 major mechanisms: (i) Na(+) influx caused by glutamatergic synaptic activity; and (ii) action-potential-mediated depolarization by Na(+) influx followed by repolarizating K(+) efflux, increasing extracellular K(+) concentration. This review deals mainly with the latter and it concludes that clearance of extracellular K(+) is initially...