“Plasma membrane calcium pump activity in rat pancreatic islets: an accurate method to measure its calcium dependent modulation”

ROSSI, J.P.F.C.; A.M. VILLAMIL

Cell biochem biophys

Año: 2006 vol. 46 p. 193 - 200

Plasma membrane calcium pump activity in rat pancreatic islets: an accurate method to measure its calcium-dependent modulation. ·     Rossi JP, ·     Villamil AM, ·     Echarte MM, ·     Alzugaray ME, ·     Borelli MI, ·     Garcia ME, ·     Pande J, ·     Grover AK, ·     Gagliardino JJ. Departamento de Quimica Biologica, Instituto de Quimica y Fisicoquimica Biologicas, Facultad de Farmacia y Bioquimica, UBA-CONICET, Buenos Aires, Argentina. jprossi@qb.ffyb.uba.ar The aim of this study was to quantify the glucose modulation of the plasma membrane calcium pump (PMCA) function in rat pancreatic islets. Ca2+-ATPase activity and levels of phosphorylated PMCA intermediates both transiently declined to a minimum in response to stimulation by glucose. Strictly dependent on Ca2+ concentration, this inhibitory effect was fully expressed at physiological concentrations of the cation (less than 0.5 muM), then progressively diminished at higher concentrations. These results, together with those previously reported on the effects of insulin secretagogues and blockers on the activity, expression and cellular distribution of the PMCA, support the concept that the PMCA plays a key role in the regulation of Ca2+ signaling and insulin secretion in pancreatic islets. PMID: 17272847 [PubMed - indexed for MEDLINE]