The Journal of General Physiology
Axon Instruments microelectrode amplifiers
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow PDF (Full Text)
Right arrow Alert me when this article is cited
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JGP
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Levitt, D. G.
Right arrow Articles by Mlekoday, H. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Levitt, D. G.
Right arrow Articles by Mlekoday, H. J.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

The Journal of General Physiology, Vol 81, 239-253, Copyright © 1983 by The Rockefeller University Press

ARTICLES

Reflection coefficient and permeability of urea and ethylene glycol in the human red cell membrane

DG Levitt and HJ Mlekoday

The reflection coefficient (sigma) and permeability (P) of urea and ethylene glycol were determined by fitting the equations of Kedem and Katchalsky (1958) to the change in light scattering produced by adding a permeable solute to a red cell suspension. The measurements incorporated three important modifications: (a) the injection artifact was eliminated by using echinocyte cells; (b) the use of an additional adjustable parameter (Km), the effective dissociation constant at the inner side of the membrane; (c) the light scattering is not directly proportional to cell volume (as is usually assumed) because refractive index and scattering properties of the cell depend on the intracellular permeable solute concentration. This necessitates calibrating for known changes in refractive index (by the addition of dextran) and cell volume (by varying the NaCl concentration). The best fit was for sigma = 0.95, Po = 8.3 X 10(-4) cm/s, and Km = 100 mM for urea and sigma = 1.0, Po = 3.9 X 10(-4) cm/s, and Km = 30 mM for ethylene glycol. The effects of the inhibitors copper, phloretin, p- chloromercuriphenylsulfonate, and 5,5'-dithiobis (2-nitro) benzoic acid on the urea, ethylene glycol, and water permeability were determined. The results suggest that there are three separate, independent transport systems: one for water, one for urea and related compounds, and one for ethylene glycol and glycerol.
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 Am. J. Physiol. Renal Physiol.Home page
B. MacIver, C. P. Smith, W. G. Hill, and M. L. Zeidel
Functional characterization of mouse urea transporters UT-A2 and UT-A3 expressed in purified Xenopus laevis oocyte plasma membranes
Am J Physiol Renal Physiol, April 1, 2008; 294(4): F956 - F964.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
B. Yang and A. S. Verkman
Analysis of Double Knockout Mice Lacking Aquaporin-1 and Urea Transporter UT-B. EVIDENCE FOR UT-B-FACILITATED WATER TRANSPORT IN ERYTHROCYTES
J. Biol. Chem., September 20, 2002; 277(39): 36782 - 36786.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
N. Roudier, J.-M. Verbavatz, C. Maurel, P. Ripoche, and F. Tacnet
Evidence for the Presence of Aquaporin-3 in Human Red Blood Cells
J. Biol. Chem., April 3, 1998; 273(14): 8407 - 8412.
[Abstract] [Full Text] [PDF]


  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents