Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
1990-11-21
pubmed:abstractText
Altered membrane proteins have been previously described in beta thalassemia and are thought to play an important role in the shortened erythrocyte survival. To investigate the mechanism by which these changes occur, purified heme-containing alpha-hemoglobin chains were entrapped within normal erythrocytes by reversible osmotic lysis. These resealed cells exhibited normal hemoglobin concentration, cell volume, deformability, and no substantial modifications of membrane proteins. Incubation (37 degrees C; up to 20 h) of the alpha-chain-loaded cells resulted in increasing amounts of membrane-associated alpha-chains. This was associated with concurrent decreases in the protein concentrations and reactive thiol groups of spectrin, ankyrin, and actin as determined by gel electrophoresis. The decreases in membrane protein concentration and reactive thiol groups after 20 h of incubation were closely correlated (R2 = 0.947) in the alpha-chain-loaded cells. Indicative of increased oxidant stress within the alpha-chain-loaded erythrocytes, methemoglobin generation was also significantly increased in the alpha-chain-loaded erythrocytes. In addition, entrapment of alpha-chains led to a progressive and significant decrease in erythrocyte deformability. Thus, the entrapment of purified alpha-chains in normal erythrocytes resulted in structural and functional abnormalities very similar to that observed in beta-thalassemic erythrocytes in vivo. The model described provides a means by which the fate of excess alpha-chains, their pathophysiological effects, as well as possible therapeutic approaches to thalassemias can be examined.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
265
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17953-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Entrapment of purified alpha-hemoglobin chains in normal erythrocytes. A model for beta thalassemia.
pubmed:affiliation
Unité de Recherche en Génétique Moléculaire et en Hématologie, Hôpital Henri Mondor, Créteil, France.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't