Linked Life Data

8460677

Source:http://linkedlifedata.com/resource/pubmed/id/8460677

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3 Pt 1
pubmed:dateCreated
1993-4-29
pubmed:abstractText
Deoxygenation of sickle cells increases membrane permeability to Na, K, and Ca and contributes to cellular cation depletion. This study examines the physiological nature of the pathway that mediates deoxygenation-induced movements of monovalent cations. Deoxygenation-induced Rb influx was a linear function of external Rb concentration, with no evidence of saturation. Activation of the deoxygenation-induced pathway was fostered by alkaline pH (7.5), whereas ion movements via the activated pathway were optimal between pH 6.9 and 7.0 in cells incubated in media in which NO3 replaced Cl to eliminate KCl cotransport. The deoxygenation-induced pathway exhibited no selectivity among the alkali metal cations Li, Na, K, Rb, or Cs, but the monovalent organic cations tetramethylammonium, tetraethylammonium, and N-methylglucamine were excluded. Sickle cells incubated in low-Cl media (external Cl, 40 mM) to depolarize the membrane exhibited increased deoxygenation-induced K efflux and reduced Na influx. Cells treated with valinomycin to hyperpolarize the membrane showed increased deoxygenation-induced Na influx. These characteristics of the deoxygenation-induced transport pathway, linear concentration dependence, lack of cation selectivity, and response to membrane potential, argue against a carrier-mediated mechanism in favor of a diffusional process. The exclusion of small organic cations, however, suggests that factors other than ion size influence deoxygenation-induced permeability.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C734-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Deoxygenation-induced cation fluxes in sickle cells. III. Cation selectivity and response to pH and membrane potential.
pubmed:affiliation
Department of Pediatrics, University of Cincinnati College of Medicine 45260.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.