P1,P5-Di(adenosine-5) pentaphosphate pentalithium salt, 94108-02-8, A(5)P5(5)A, AC1O4WDE, D6392_SIGMA, CTK8G2238, EINECS 302-339-2, AP5A lithium salt P1,P5-Di(adenosine-5) pentaphosphate pentalithium salt, AG-H-86941, Diadenosine pentaphosphate trilithium salt, Diadenosine pentaphosphate pentalithium salt, K00187, A(5 inverted exclamation marka)P5(5 inverted exclamation marka)A trilithium salt, Adenosine 5-(hexahydrogen pentaphosphate), 5.5-ester with adenosine, pentalithium salt, P1,P5-Di(adenosine-5 inverted exclamation marka) pentaphosphate trilithium salt, 75522-97-3, pentalithium bis[[[(2R,3S,4R,5R)-5-(6-aminopurin-9-yl)-3,4-dihydroxyoxolan-2-yl]methoxy-oxidophosphoryl]oxy-oxidophosphoryl] phosphate

A diadenosine polyphosphate stored in secretory granules of thrombocytes, chromaffin and neuronal cells. After release into the extracellular space, it affects a variety of biological activities in a wide range of target tissues. In the nervous system it acts through various purinergic receptors. It also activates 5′-nucleotidase and inhibits adenosine kinase activity in vitro. Ap5A is metabolized by soluble enzymes in the blood plasma and by membrane-bound ectoenzymes of a number of cell types including endothelial and smooth muscle cells. In cardiac muscle, pM to nM concentrations significantly increase the open-probability of ryanodine-receptor (RyR2) gates, with prolonged action due to slow dissociation from the receptor.