title: Characterization and quantification of diadenosine hexaphosphate in chromaffin cells: granular storage and secretagogue-induced release.
abstract: The presence of diadenosine hexaphosphate (Ap6A) in chromaffin cells is described. The characterization of Ap6A has been accomplished by HPLC techniques, using three different elution conditions, rechromatography, and coelution with standards. Treatment with phosphodiesterase from Crotalus durissus produced AMP and adenosine pentaphosphate. The HPLC techniques described allowed the quantification of Ap6A in the picomole range. Chromaffin granules store Ap6A in a quantity of 48.5 +/- 9.7 nmol/mg protein, with a molar ratio ATP/Ap6A of 27. In chromaffin cells the Ap6A value was 1.46 +/- 0.32 nmol/10(6) cells. Diadenosine hexaphosphate was released from chromaffin cells by the action of carbachol and a value of 64 +/- 15 pmol/10(6) cells was obtained, which represents 4-5% of the total cellular content.
authors.affiliation: Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense de Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Pintor
authors.forename: P
authors.initials: P
authors.lastname: Rotllán
authors.forename: M
authors.initials: M
authors.lastname: Torres
authors.forename: M T
authors.initials: MT
authors.lastname: Miras-Portugal
mesh_terms: D000313:Adrenal Medulla / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D002837:Chromaffin Granules / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D015226:Dinucleoside Phosphates / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics
chemical_list: D015226:Dinucleoside Phosphates; C070070:diadenosine 5',5''''-P1,P6-hexaphosphate; D002217:Carbachol