Cross-talk between adenosine and opioid receptors.

Opioid and adenosine receptors are implicated in numerous physiological and pathophysiological states. Moreover, both G-protein-coupled receptor families have been demonstrated to provide significant protection against ischemic injury in the myocardium and central nervous system (CNS). Much recent data report a tight interaction between these two receptor families, from alterations in receptor sensitivity to release of endogenous adenosine in the presence of morphine. Indeed, it appears that the cardioprotective effects of adenosine can be abolished by opioid receptor antagonists and vice-versa. This review aims to highlight some of the research, derived from both the CNS and myocardium, supporting this interesting interaction.