Involvement of adenosine A1 and A2A receptors in the motor effects of caffeine after its acute and chronic administration
Φόρτωση...
Ημερομηνία
Συγγραφείς
Karcz-Kubicha, M.
Antoniou, K.
Terasmaa, A.
Quarta, D.
Solinas, M.
Justinova, Z.
Pezzola, A.
Reggio, R.
Muller, C. E.
Fuxe, K.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer-reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Neuropsychopharmacology
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The involvement of adenosine A(1) and A(2A) receptors in the motor effects of caffeine is still a matter of debate. In the present study, counteraction of the motor-depressant effects of the selective A(1) receptor agonist CPA and the A(2A) receptor agonist CGS 21680 by caffeine, the selective A(1) receptor antagonist CPT, and the A(2A) receptor antagonist MSX-3 was compared. CPT and MSX-3 produced motor activation at the same doses that selectively counteracted motor depression induced by CPA and CGS 21680, respectively. Caffeine also counteracted motor depression induced by CPA and CGS 21680 at doses that produced motor activation. However, caffeine was less effective than CPT at counteracting CPA and even less effective than MSX-3 at counteracting CGS 21680. On the other hand, when administered alone in habituated animals, caffeine produced stronger motor activation than CPT or MSX-3. An additive effect on motor activation was obtained when CPT and MSX-3 were coadministered. Altogether, these results suggest that the motor-activating effects of acutely administered caffeine in rats involve the central blockade of both A(1) and A(2A) receptors. Chronic exposure to caffeine in the drinking water (1.0 mg/ml) resulted in tolerance to the motor effects of an acute administration of caffeine, lack of tolerance to amphetamine, apparent tolerance to MSX-3 (shift to the left of its 'bell-shaped' dose-response curve), and true cross-tolerance to CPT. The present results suggest that development of tolerance to the effects of A(1) receptor blockade might be mostly responsible for the tolerance to the motor-activating effects of caffeine and that the residual motor-activating effects of caffeine in tolerant individuals might be mostly because of A(2A) receptor blockade.
Περιγραφή
Λέξεις-κλειδιά
Adenosine/*analogs & derivatives/pharmacology, Amphetamine/pharmacology, Animals, Behavior, Animal, Caffeine/*administration & dosage, Central Nervous System Stimulants/*administration & dosage, Dose-Response Relationship, Drug, Drug Administration Schedule/veterinary, Drug Interactions, Male, Motor Activity/*drug effects, Phenethylamines/pharmacology, Purinergic P1 Receptor Agonists, Purinergic P1 Receptor Antagonists, Radioligand Assay/methods, Rats, Rats, Sprague-Dawley, Receptor, Adenosine A2A, Receptors, Purinergic P1/*physiology, Theophylline/*analogs & derivatives/pharmacology, Time Factors, Triazines/pharmacokinetics, Triazoles/pharmacokinetics, Tritium/pharmacokinetics, Xanthines/pharmacokinetics/pharmacology
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
http://www.ncbi.nlm.nih.gov/pubmed/12700682
http://www.nature.com/npp/journal/v28/n7/pdf/1300167a.pdf
http://www.nature.com/npp/journal/v28/n7/pdf/1300167a.pdf
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικής