In recent years, many groups of clinical scientists have become interested in measuring transmembrane ion fluxes of various kinds in patients with different diseases. The ion fluxes of interest have included the ouabainsensitive Na+/K+ pump, the loop-diuretic-sensitive Na+/ K+ co-transport system, the phloretin-sensitive Na+/Na+ (or Na+/Li+ ) countertransport system, and the amiloridesensitive ...

Investigation of the transport properties of ions confined in nanoporous carbon is generally difficult because of the stochastic nature and distribution of multiscale complex and imperfect pore structures within the bulk material. We demonstrate a combined approach of experiment and simulation to describe the structure of complex layered graphene-based membranes, which allows their use as a uni...

Glutamate transport via the human excitatory amino acid transporters is coupled to the co-transport of three Na(+) ions, one H(+) and the counter-transport of one K(+) ion. Transport by an archaeal homologue of the human glutamate transporters, Glt(Ph), whose three dimensional structure is known is also coupled to three Na(+) ions but only two Na(+) ion binding sites have been observed in the c...

Ion permeation through transmembrane channels has traditionally been modeled using two different approaches. In one approach, the translocation of the permeant ion through the channel pore is modeled as continuous diffusion and the rate of ion transport is obtained from solving the steady-state diffusion equation. In the other approach, the translocation of the permeant ion through the pore is ...

UNLABELLED Somatostatin increases absorption of electrolytes and inhibits diarrhea in patients with endocrine tumors and short bowel syndrome. In an attempt to develop a gut-specific somatostatin analog, each amino acid in the somatostatin molecule was replaced with L-alanine, deleted, or substituted with its D-isomer. The potency of each analog to stimulate ion transport in the rabbit ileum wa...

We extend a model of ion and water transport through a root to describe transport along and through a root exhibiting a complexity of differentiation zones. Attention is focused on convective and diffusive transport, both radially and longitudinally, through different root tissue types (radial differentiation) and root developmental zones (longitudinal differentiation). Model transport paramete...

A bstract. Canine tracheal epithelium secretes Cl and absorbs Na; the energy for both is derived from the activity of the basolateral membrane Na-K-ATPase. These properties allowed us to examine the energetics of C1 secretion by directly comparing the metabolic cost of Cl transport with the metabolic cost ofNa transport. We measured the change in short-circuit current and 02 consumption rate th...

Peng J-B, Warnock DG. WNK4-mediated regulation of renal ion transport proteins. Am J Physiol Renal Physiol 293: F961–F973, 2007. First published July 18, 2007; doi:10.1152/ajprenal.00192.2007.—Point mutations in WNK4 [for With No K (lysine)], a serine-threonine kinase that is expressed in the distal nephron of the kidney, are linked to familial hyperkalemic hypertension (FHH). The imbalanced el...