Linked Life Data

3374267

Source:http://linkedlifedata.com/resource/pubmed/id/3374267

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
1988-7-8
pubmed:abstractText
Rats treated chronically with caffeine become tolerant to caffeine-induced stimulation of locomotor activity and cross-tolerant to theophylline. This study was performed to determine if the cross-tolerance between these two methylxanthine drugs is symmetrical. Symmetrical cross-tolerance produced by two different drugs implies a common underlying mechanism of action. Separate groups of rats were given scheduled access to drinking bottles containing either drug-free tap water or 1.0 mg/ml theophylline solution. Daily theophylline intake averaged 59 mg/kg. Dose-effect curves were determined in both control and theophylline-treated groups for 5 drugs: the methylxanthines theophylline and caffeine, a nonxanthine psychomotor stimulant, d-amphetamine, and the adenosine analogs R(-)-N6-2-(phenylisopropyl)adenosine and 5'-(N-ethyl)carboxamidoadenosine. All drugs were injected i.p. and locomotor activity was measured for 30 min beginning 35 min later. Rats that were maintained chronically on theophylline were completely tolerant to the locomotor activity stimulant effects of acutely administered theophylline and cross-tolerant to caffeine-induced stimulation of locomotor activity. In contrast, both control and treated groups were fully responsive to the stimulant effects of d-amphetamine. Low doses of the adenosine analogs produced stimulation of locomotor activity in both groups of rats. Higher doses produced a dose-dependent depression of locomotor activity in control rats; curves for the theophylline-treated rats were shifted to the right of the control curves. Thus, adenosine antagonist activity of theophylline remained evident at a time of complete tolerance to the stimulant effect of the drug on locomotor activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0024-3205
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2475-82
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Tolerance and cross-tolerance to theophylline-induced stimulation of locomotor activity in rats.
pubmed:affiliation
Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.