P¹,P⁴-Di(adenosine-5′) tetraphosphate ammonium salt 

Diadenosine polyphosphate functions as a second messenger in pancreatic cells, stimulates phospholipase D, changes intracellular calcium levels, induces nitric oxide release, activates 5'-nucleotidase, and inhibits adenosine kinase activity in vitro.

Diadenosine polyphosphate is 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. It appears to function as a second messenger in pancreatic cells. In rat liver cells. it stimulates phospholipase D and changes intracellular calcium levels. It has been shown to induce nitric oxide release from endothelial cells. In the nervous system it acts through various purinoceptors. It also activates 5'-nucleotidase and inhibits adenosine kinase activity in vitro. Ap4A is metabolized by soluble enzymes in the blood plasma and by membrane-bound ectoenzymes of a number of cell types including endothelial cells, smooth muscle cell.

~95% (HPLC)

powder

white

H₂O: 50 mg/mL

human ... PLD1(5337), PLD2(5338), PLD3(23646), PLD4(122618), PLD5(200150)

−20°C

Edgecombe, M., et al., Diadenosine polyphosphate-stimulated gluconeogenesis in isolated rat proximal tubules. Biochem. J. 323, 451-456, (1997) abstract

Wildman, S.S., et al., Selectivity of diadenosine polyphosphates for rat P2X receptor subunits. Eur. J. Pharmacol. 367, 19-123, (1999)

Delaney, S.M., et al., Diadenosine polyphosphates inhibit adenosine kinase activity but decrease levels of endogenous adenosine in rat brain. Eur. J. Pharmacol. 322, 5-42, (1997)

Blouse, G.E., et al., Characterization of ATP and P2 agonists binding to the cardiac plasma membrane P1,P4-diadenosine 5'-tetraphosphate receptor. Biochim. Biophys. Acta 1375, 61-72, (1998) abstract

Hilderman, R.H., Christensen, E.F., P¹P⁴-diadenosine 5' tetraphosphate induces nitric oxide release from bovine aortic endothelial cells. FEBS Lett. 427, 320, (1998) abstract

Ogilvie, A., et al., Adenine dinucleotides: a novel class of signalling molecules. J. Auton. Pharmacol. 16, 325-328, (1996) abstract

Verspohl, E.J., and Johannwille, B., Diadenosine polyphosphates in insulin-secreting cells: interaction with specific receptors and degradation. Diabetes 47, 1727-1734, (1998) abstract

Edgecombe, M., et al., Diadenosine polyphosphate-mediated activation of phospholipase D in isolated rat liver cells. Cell. Signal. 10, 505-509, (1998) abstract

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AU7411600