Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2 Pt 1
pubmed:dateCreated
1988-9-14
pubmed:abstractText
Recent studies suggest that the utilization of oxidizable substrates by the brain may be regulated in part by transport across the plasma membrane. Dissociated brain cells obtained by mechanical disruption of rat brain were used to measure the uptake of 3-hydroxy[3-14C]butyrate. Total uptake revealed two mechanisms (diffusion and a carrier-mediated system). A Lineweaver-Burk plot of the latter component yielded an apparent Km of 1.47 mM and a maximal velocity (Vmax) of 5 nmol.min-1.mg protein-1. The rates of uptake were temperature dependent and were significantly higher at pH 6.2 than at pH 7.4 or 8.2. Preloading the cells and increasing the intracellular concentration of 3-hydroxybutyrate using 12.5 and 25 mM increased the rate of uptake 143 and 206%, respectively, indicative of an accelerative exchange mechanism. Uptake was inhibited approximately 50% by (in mM) 10 phenylpyruvate, 10 alpha-ketoisocaproate, 10 KCN, and 1.5 NaAsO2. Uptake was also decreased by (in mM) 5 lactate, 5 methyl malonic acid, 1 alpha-cyano-4-hydroxycinnamate, and 1 mersalyl. Dissociated brain cells from 14- to 16-day-old rats accumulated 3-hydroxybutyrate at a rate more than two-fold greater than cells from either younger (2-day-old) or older (28-day-old and adult) animals. These data are consistent with the proposal that 3-hydroxybutyrate is taken up by the brain by both diffusion and a carrier-mediated transport system, and they support the hypothesis that transport at the cellular level contributes to the regulation of substrate utilization by the brain.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
255
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C133-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Transport of 3-hydroxy[3-14C]butyrate by dissociated cells from rat brain.
pubmed:affiliation
Department of Pediatrics, University of Maryland School of Medicine, Baltimore 21201.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.