Linked Life Data

11477212

Source:http://linkedlifedata.com/resource/pubmed/id/11477212

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-7-30
pubmed:abstractText
Methylxanthines such as caffeine and theophylline are known to inhibit glucose transport. We have studied such inhibition in the glucose transporter type 1 deficiency syndrome (Glut1DS) by erythrocyte glucose transport assays. Data from four patients with individual mutations in the GLUT1 gene are discussed: patient 1 (hemizygosity), 3 (S66F), 15 (368Ins23), and 17 (R333W). Zero-trans influx of (14)C-labeled 3-O-methyl glucose (3-OMG) into erythrocytes of patients is reduced (patient 1, 51%; 3, 45%; 15, 31%; 17, 52%) compared with maternal controls. Inhibition studies on patients 1, 3, 17, and maternal controls show an IC(50) for caffeine of approximately 1.5 mM both in controls (n = 3) and patients (n = 3) at 5 mM 3-OMG concentration. In the same two groups, kinetic studies show that 3 mM caffeine significantly decreases V(max) (p < 0.005), whereas the decrease in K(m) is significant (p < 0.01) only in the three controls and one patient (patient 3). Kinetic data from individual patients permit us to speculate that the interactions between caffeine and Glut1 are influenced by the mutation. Three mM caffeine also inhibits the transport of dehydroascorbic acid (DHA), another substrate for Glut1. The combined effects of caffeine (3 mM) and phenobarbital (10 mM) on glucose transport, as determined in patient 15 and the maternal control, show no additive or synergistic inhibition. These data indicate that caffeine and phenobarbital have similar Glut1 inhibitory properties in these two subjects. Our study suggests that Glut1DS patients may have a reduced safety margin for methylxanthines. Consumption of methylxanthine-containing products may aggravate the neurologic symptoms associated with the Glut1DS.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0031-3998
pubmed:author
pubmed:issnType
Print
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
254-60
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Glucose transporter type 1 deficiency syndrome (Glut1DS): methylxanthines potentiate GLUT1 haploinsufficiency in vitro.
pubmed:affiliation
Department of Neurology, Columbia University, 710 West 168th Street, New York, NY 10032, U.S.A.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Case Reports, Research Support, Non-U.S. Gov't