Adenosine 3′-monophosphate (3′-AMP) sodium salt is a metabolite of 2′,3′-cAMP by a family of metal-dependent phosphodiesterases. 3′-AMP has been shown to inhibit the proliferation of preglomerular vascular smooth muscle cells and glomerular mesangial cells via A2B receptors. This may present a new unexplored pathway for adenosine-based cell regulation.