Regulation of adenosine receptors in rat brain following chronic carbamazepine treatment.
- Author:
Kyung Sun PARK
1
;
Wan Suk YANG
;
Kyung Hwan KIM
Author Information
1. Department of Pharmacology and Institute of Basic Medical Sciences, Wonju College of Medicine, Yonsei University, Wonju 220-701 South Korea.
- Publication Type:Original Article
- Keywords:
Carbamazepine;
Al Adenosine receptor;
Cerebral cortex
- MeSH:
Adenosine*;
Adenylyl Cyclases;
Animals;
Brain*;
Carbamazepine*;
Cerebral Cortex;
GTP-Binding Proteins;
Ligands;
Membranes;
Rats*;
Receptors, Purinergic P1*
- From:The Korean Journal of Physiology and Pharmacology
1997;1(1):13-17
- CountryRepublic of Korea
- Language:English
-
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.
