The present address of Dr. A. K. Dixon is The Sanger Centre, Hinxton Hall, Hinxton, Cambridge, CB10 1SA, U.K.
Desensitisation of the Adenosine A1 Receptor by the A2A Receptor in the Rat Striatum
Article first published online: 18 NOV 2002
Journal of Neurochemistry
Volume 69, Issue 1, pages 315–321, July 1997
How to Cite
Dixon, A. K., Widdowson, L. and Richardson, P. J. (1997), Desensitisation of the Adenosine A1 Receptor by the A2A Receptor in the Rat Striatum. Journal of Neurochemistry, 69: 315–321. doi: 10.1046/j.1471-4159.1997.69010315.x
- Issue published online: 18 NOV 2002
- Article first published online: 18 NOV 2002
- Received October 22, 1996; revised manuscript received February 13, 1997; accepted February 13, 1997.
- Adenosine receptor;
- Protein kinase C;
Abstract: The influence of the adenosine A2A receptor on the A1 receptor was examined in rat striatal nerve terminals, a model for other cells in which these receptors are coexpressed. Incubation of striatal synaptosomes with the A2A receptor agonist 2-p-(2-carboxyethyl)phenethylamino-5′-N-ethylcarboxamidoadenosine (CGS 21680) caused the appearance of a low-affinity binding site for the A1 receptor agonist 2-chloro-N6-cyclopentyladenosine (CCPA). This effect was blocked by the A2A receptor antagonist ZM241385 and by the protein kinase C inhibitor chelerythrine, but not by the protein kinase A inhibitor N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA 1004). The effect was not seen with striatal membranes or with hypotonically lysed synaptosomes. These results demonstrate a protein kinase C-mediated heterologous desensitisation of the A1 receptor by the A2A receptor.
Abbreviations used: CCPA, 2-chloro-N6-cyclopentyladenosine; CGS 21680, 2-p-(2-carboxyethyl)phenethylamino-5′-N-ethylcarboxamidoadenosine; DPCPX, 8-cyclopentyl-1,3-dipropylxanthine; HA 1004, N-(2-guanidinoethyl)-5-isoquinolinesulfonamide; ZM241385, 4-[2-[7-amino-2-(2-furyl)(1,2,4)-triazin-5-ylamino]-ethyl]phenol.