Oatp2 Mediates Bidirectional Organic Solute Transport: A Role for Intracellular Glutathione

2000 ◽  
Vol 58 (2) ◽  
pp. 335-340 ◽  
Author(s):  
Liqiong Li ◽  
Peter J. Meier ◽  
Nazzareno Ballatori
Keyword(s):  
Solute Transport ◽  
Intracellular Glutathione ◽  
Organic Solute

scholarly journals Solute Transport Controls Membrane Tension and Organellar Volume

2021 ◽  
Vol 55 (S1) ◽  
pp. 1-24
Keyword(s):  
Solute Transport ◽  
Endocytic Pathway ◽  
Coat Proteins ◽  
Lysosomal Storage ◽  
Transport Pathways ◽  
Osmotic Change ◽  
Solute Fluxes ◽  
Organic Solute ◽  
Membrane Bound ◽  
Sense And Respond

The regulation of cellular volume in response to osmotic change has largely been studied at the whole cell level. Such regulation occurs by the inhibition or activation of ionic and organic solute transport pathways at the cell surface and is coincident with remodelling of the plasma membrane. However, it is only in rare instances that osmotic insults are experienced by cells and tissues. By contrast, the relatively minute luminal volumes of membrane-bound organelles are constantly subject to shifts in their solute concentrations as exemplified in the endocytic pathway where these evolve alongside with maturation. In this review, we summarize recent evidence that suggests trafficking events are in fact orchestrated by the solute fluxes of organelles that briefly impose osmotic gradients. We first describe how hydrostatic pressure and the resultant tension on endomembranes can be readily dissipated by controlled solute efflux since water is obliged to exit. In such cases, the relief of tension on the limiting membrane of the organelle can promote its remodelling by coat proteins, ESCRT machinery, and motors. Second, and reciprocally, we propose that osmotic gradients between organellar lumens and the cytosol may persist or be created. Such gradients impose osmotic pressure and tension on the endomembrane that prevent its remodelling. The control of endomembrane tension is dysregulated in lysosomal storage disorders and can be usurped by pathogens in endolysosomes. Since trafficking and signaling pathways conceivably sense and respond to endomembrane tension, we anticipate that understanding how cells control organellar volumes and the movement of endocytic fluid in particular will be an exciting new area of research.

scholarly journals Renal tubular mechanisms of organic solute transport

1976 ◽  
Vol 9 (2) ◽  
pp. 134-148 ◽  
Author(s):  
Karl J. Ullrich
Keyword(s):  
Solute Transport ◽  
Organic Solute ◽  
Renal Tubular

A 19F and 2H NMR Spectroscopic Investigation of the Interaction Between Nonionic Organic Contaminants and Dissolved Humic Material

1997 ◽  
Author(s):  
Bruce E. Herbert ◽  
Paul M. Bertsch
Keyword(s):  
Organic Matter ◽  
Solute Transport ◽  
Organic Contaminants ◽  
Chemical Interaction ◽  
Chemical Shifts ◽  
Sodium Dodecyl ◽  
High Sensitivity ◽  
Humic Material ◽  
Matter Interaction ◽  
Organic Solute

Interaction between nonionic organic contaminants (NOC) and natural organic matter strongly influences the fate and transport of NOC in the environment. Microscopic descriptions of NOC-organic matter interaction have been developed based on macroscopic observations of NOC sorption to organic matter and organic solute transport under varying conditions. These models include the partitioning concept describing NOC sorption to organic matter and the concept of intra-organic matter diffusion used to account for nonequilibrium organic solute transport; however, little microscopic information exists to validate them. NMR may be a powerful method to gain information and insight concerning NOC-organic matter interaction. Chemical shifts, linewidths, and the magnitude of spin-spin couplings exhibited in the NMR spectra of a given nucleus are dependent on the characteristics of the surrounding media and therefore can be used to study the NOC-organic matter interaction. NMR characterization of the chemical interaction between NOC and organic matter can potentially provide information on important aspects of the sorption mechanism. This information may be useful to explain the influence of organic matter characteristics on NOC sorption and the mechanisms controlling nonequilibrium sorption of NOC to organic matter and mineral phases, and to evaluate different conceptual models of natural humic material, including the polymer concept, where humics are considered to be flexible linear polyelectrolytes, and the micelle concept, which considers humics to be aggregates of simple organic compounds, oligomers, and humic molecules ultimately forming micellar-type structures. NMR has been used to study the interactions of small organic solutes with macromolecules and organized organic assemblies. Fluorine-19 NMR has been particularly useful to study these interactions because this magnetically active nucleus is 100% abundant, has a high sensitivity (83% of 1H) and large chemical shift range, and exhibits no background signal. Several NMR studies have followed the interactions between fluorinated anesthetics and phospholipids, sodium dodecyl sulfate (SDS) micelles, and intact rabbit brain tissue. Generally, these studies have indicated both that sorption sites are less polar than aqueous solutions and that there is decreased mobility of the sorbed solute. Fluorine-19 NMR has also been used to characterize the interactions between fluorine-containing ligands, such as fluorotryptophan, and human serum albumin (HSA).

Control of Rate of Solute Transport in Newly Developed Portable Agar Gel Blood Purification System

1998 ◽  
Vol 2 (1) ◽  
pp. 67-70
Author(s):  
Akihiro C. Yamashita ◽  
Ryoichi Sakiyama ◽  
Hiroyuki Hamada ◽  
Kakuji J. Tojo
Keyword(s):  
Solute Transport ◽  
Blood Purification ◽  
Agar Gel ◽  
Purification System
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