The purpose of this study was to examine the regulation of A 2A adenosine receptor (A 2A AR) gene expression induced by proinflammatory cytokines in PC12 cells. The A 2A AR mRNA levels were substantially increased following 3–48hr PC12 cell treatment with interleukin 1 beta (500unit/mL) or tumor necrosis factor alpha (1000unit/mL), as revealed by RT-PCR analysis. In parallel, cell cytokine treatment induced an up-regulation of A 2A receptor protein. Equilibrium radioligand binding studies on treated-cells showed a significant increase in maximum density of [3H] 2-(carboxyethylphenylethylamino) adenosine-5′-carboxamide binding sites, with no significant changes in the affinity constant value. The increase in A 2A receptor density was also demonstrated by Western blot analysis. Interleukin 1 beta and tumor necrosis factor alpha effects on A 2A AR mRNA and protein levels were detectable after 3hr cytokine treatment and reached a maximum within 24 and 48hr, respectively. These results demonstrated the existence of heterologous regulation of A 2A ARs by proinflammatory cytokines. The biological significance of this regulation might be associated with modulating cellular activity in response to tissue damage associated with inflammatory mediator production.