Korean J Physiol Pharmacol.  1997 Feb;1(1):13-17.

Regulation of adenosine receptors in rat brain following chronic carbamazepine treatment

• Park KS
• Yang WS
• Kim KH

Abstract

Carbamazepine (CBZ), an anticonvulsant, has been reported to displace ligands at adenosine receptors. Several studies have demonstrated that as far as A-2 adenosine receptors is concerned, CBZ acts as an antagonist. However, the situation with regard to A-1 receptors is less straightforward. In this study, we describe the effects of one-week CBZ treatment (25 mg/kg/day) on cerebrocortical A-1 adenosine receptors. A-1 adenosine receptor bindings as determined by using (3H)DPCPX was not significantly altered in membranes prepared from CBZ-treated rats. However, there was a significant decrease in the A, adenosine receptor-mediated stimulation of (35S)GTP-gamma-S binding to cerebrocortical membranes prepared from CBZ-treated rats (20.0% decrease in basal activity; 17.8% decrease in maximal activity). The basal and 10-4 M forskolin-stimulated adenylyl cyclase activities were relatively unaffected by CBZ treatment, but 10 mM NaF-stimulated adenylyl cyclase activity was significantly reduced in CBZ-treated rats. It appears that one-week CBZ treatment caused an uncoupling of adenosine receptors from G proteins without alteration of A-1 adenosine receptor molecules, suggesting that CBZ acts as an agonist at A-1 adenosine receptors in rat brain.

Keyword

Carbamazepine; Al Adenosine receptor; Cerebral cortex

MeSH Terms

Adenosine*
Adenylyl Cyclases
Animals
Brain*
Carbamazepine*
Cerebral Cortex
GTP-Binding Proteins
Ligands
Membranes
Rats*
Receptors, Purinergic P1*
Adenosine
Carbamazepine
GTP-Binding Proteins
Ligands
Receptors, Purinergic P1