Calcium mobilization in Jurkat cells via A 2b adenosine receptors

1 A functional study of cell surface A 2b adenosine receptors was performed on the T cell leukaemia line, Jurkat. 2 A 2b receptors were coupled both to the adenylate cyclase system and to intracellular calcium channels. In fact, the agonist of A 2b receptors, 5′‐ N ‐ethylcarboxamidoadenosine (NECA), led to a transient accumulation of intracellular calcium by an inositol phosphate‐independent mechanism. 3 The NECA‐induced accumulation of cGMP was not responsible for the calcium mobilization via A 2b receptors. 4 The calcium response elicited by activation of A 2b receptors was independent of that evoked by activation of the T cell receptor. 5 These findings not only delineate a novel transduction mechanism for adenosine but also support a specific role for adenosine in modulating signals elicited via the T cell receptor.British Journal of Pharmacology (1997) 122 , 1075–1082; doi: 10.1038/sj.bjp.0701495