Adenosine uptake transporters and receptors

The adenosine signaling system is a complex network involving cell-surface G protein-coupled receptors and transmembrane nucleoside transporters that regulate the concentration and physiological effects of extracellular adenosine. There are four distinct adenosine receptor subtypes—A1, A2A, A2B, and A3—which mediate diverse biological processes such as vasodilation, cardiac rhythm regulation, and immune suppression (Fredholm et al., 2011). The extracellular levels of adenosine are primarily controlled by equilibrative nucleoside transporters (ENTs), particularly ENT1 and ENT2, which facilitate the uptake of adenosine into cells for metabolic processing (Young et al., 2013). Pharmacological intervention in this system includes the use of uptake inhibitors like dipyridamole to enhance endogenous adenosine signaling, as well as direct receptor agonists like regadenoson for cardiac imaging or antagonists like caffeine for central nervous system stimulation (Chen et al., 2013). This system plays a pivotal role in the "retaliatory" response to cellular stress, protecting tissues from ischemia and excessive inflammation (Eltzschig et al., 2012).

Other names

Nucleoside transportersP1 receptorsAdenosine signaling systemEquilibrative nucleoside transportersConcentrative nucleoside transportersAdenosine receptor subtypes

Inhibition of equilibrative nucleoside transporters (ENTs) to increase extracellular adenosine levels, or direct agonism/antagonism of G protein-coupled adenosine receptors (A1, A2A, A2B, A3).