A2B Adenosine receptor, pAb

The various adenosine receptors can be distinguished on the basis of their differential selectivity for adenosine analogs^1-3. The A₂ Adenosine receptor subtype was subdivided according to affinity for adenosine; A2AAR has high affinity and A2BAR has low affinity for adenosine. A2BAR is expressed in mast cells, neutrophils, monocytes, macrophages, dendritic cells, T cells, bronchial epithelium, intestinal epithelium, smooth muscle, brain, and other cells⁵. In intestinal epithelia, A2BAR was found to be the major adenosine receptor subtype expressed and is thought to be involved in diarrheal diseases. It is also believed to be involved in the pathogenesis of chronic airway inflammatory diseases⁴. Antagonists of A2BAR may be effective for the treatment of inflammatory gastrointestinal tract disorders⁴ as well as asthma and chronic obstructive pulmonary disease⁵.