Document Detail


Fast and slow fractions of K+ flux in human lymphocytes.
MedLine Citation:
PMID:  438298     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Potassium influx and efflux were studied in human peripheral blood lymphocytes equilibrated over a wide range of external K+ levels. The absence of a net ion movement throughout the flux study was established, trapped space was measured with polyethylene glycol, and cells were separated from incubation media without exposure to any washing solution. There are both rapid and slow cellular fractions of 42K influx and efflux, and half-times of exchange of around 2 minutes, and 400 minutes, respectively. The rapid component is identical in magnitude to the smaller non-saturable component of cell K+, while the slow component is identified with the larger, sigmoidal, saturable component of cell K+ that was previously shown to follow a cooperative adsorption isotherm. These results support the association-induction hypothesis, which predicts (a) a rapid fraction of K+ flux due to equilibration of ion within cell water existing in a state of polarized multilayers, and (b) a slower component of K+ flux limited by adsorption onto, or desorption from, fixed anionic sites existing throughout the cell. K+ influx, as a function of external K+, showed a triphasic relation with a peak around 1 mM K+ex, then a trough around 4mM K+ex, and then a gradual rise. This relation was readily explained, in terms of the association-induction hypothesis, by the cooperative interaction between, and ion occupancy of, fixed anionic sites that adsorb K+ or Na+.
Authors:
W Negendank; C Shaller
Related Documents :
7524338 - Phi and serum regulate ae2-mediated cl-/hco3- exchange in chop cells of defined transie...
15596438 - Regulation of intracellular cl- concentration through volume-regulated clc-3 chloride c...
7130948 - Vaccinia virus-induced changes in [na+] and [k+] in hela cells.
1319688 - Identification of na(+)-h+ exchange in human normal and cystic fibrotic ciliated airway...
11249068 - Arip cells as a model for pancreatic beta cell growth and development.
10783138 - Direct interaction of gd3 ganglioside with mitochondria generates reactive oxygen speci...
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Journal of cellular physiology     Volume:  98     ISSN:  0021-9541     ISO Abbreviation:  J. Cell. Physiol.     Publication Date:  1979 Mar 
Date Detail:
Created Date:  1979-07-25     Completed Date:  1979-07-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0050222     Medline TA:  J Cell Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  539-52     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Cell Compartmentation
Cell Membrane / metabolism
Extracellular Space / metabolism
Humans
Intracellular Fluid / metabolism
Kinetics
Lymphocytes / metabolism*
Models, Biological
Potassium / blood*
Sodium / metabolism
Water-Electrolyte Balance
Chemical
Reg. No./Substance:
7440-09-7/Potassium; 7440-23-5/Sodium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  A comparative study of glycosaminoglycans in cultures of human, normal and malignant glial cells.
Next Document:  Selective suppression of the transcription of ribosomal genes in mouse-human hybrid cells.