Linked Life Data

11891583

Source:http://linkedlifedata.com/resource/pubmed/id/11891583

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2002-3-13
pubmed:abstractText
Triads and transverse tubules isolated from mammalian skeletal muscle actively accumulated Na+ in the presence of K+ and Mg-ATP. Active Na+ transport exhibited a fast single-exponential phase, lasting 2 min, followed by slower linear uptake that continued for 10 minutes. Valinomycin stimulated Na+ uptake, suggesting it decreased a pump-generated membrane potential gradient (Vm) that prevented further Na+ accumulation. At the end of the fast uptake phase transverse tubule vesicles incubated in 30 mM external [Na+] attained a ratio [Na+]in/[Na+]out=13.4. From this ratio and the transverse tubule volume of 0.35 microl/mg protein measured in this work, [Na+]in=400 mM was calculated. Determinations of active K+ transport in triads, using 86Rb+ as tracer, showed a 30% decrease in vesicular 86Rb+ content two minutes after initiating the reaction, followed by a slower uptake phase during which vesicles regained their initial 86Rb+ content after 10 minutes. Transverse tubule volume increase during active Na+ transport-as shown by light scattering changes of isolated vesicles--presumably accounted for the secondary Na+ and 86Rb+ uptake phases. These combined results indicate that isolated triads have highly sealed transverse tubules that can be polarized effectively by the Na+ pump through the generation of significant Na+ gradients.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
185
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
257-63
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Sodium transport in triads isolated from rabbit skeletal muscle.
pubmed:affiliation
Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Casilla 70005, Santiago 7, Chile. pdonoso@machi.med.uchile.cl
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't