CENEXA   05419
CENTRO DE ENDOCRINOLOGIA EXPERIMENTAL Y APLICADA
Unidad Ejecutora - UE
artículos
Título:
Cardiac microvascular endothelial cells express a functional Ca2+-sensing receptor
Autor/es:
ROBERTO BERRA ROMANI; ABDUL RAQEEB; UMBERTO LAFORENZA; MANUELA FEDERICA SCAFFINO; FRANCESCO MOCCIA; JOSÈ EVERARDO AVELINO CRUZ; AMANDA OLDANI; DANIELA COLTRINI; VERONICA MILESI; VANNI TAGLIETTI; FRANCO TANZI
Revista:
JOURNAL OF VASCULAR RESEARCH.
Editorial:
KARGER
Referencias:
Año: 2009 vol. 46 p. 73 - 82
ISSN:
1018-1172
Resumen:
The mechanism whereby extracellular Ca2+ exerts the endothelium-dependent control of vascular tone is still unclear. In this study, we assessed whether cardiac microvascular endothelial cells (CMEC) express a functional extracellular Ca2+-sensing receptor (CaSR) by using a variety of techniques. CaSR mRNA was detected by using RT-PCR, and CaSR protein was identified by immunocytochemical analysis. In order to assess the functionality of the receptor, CMEC were loaded with the Ca2+-sensitive fluorochrome, Fura-2/AM. A number of CaSR agonists, such as spermine, Gd3+, La3+ and neomycin, elicited a heterogeneous intracellular Ca2+ signal, which was abolished by disruption of InsP3 signalling and by depletion of intracellular stores with CPA. The inhibition of Na+/Ca2+ exchanger upon substitution of extracellular Na+ unmasked the Ca2+ signal triggered by an increase in extracellular Ca2+ levels. Finally, aromatic amino acids, which function as allosteric activators of CaSR, potentiated the Ca2+ response to the CaSR agonist, La3+. These data provide evidence that CMEC express a CaSR which is able to respond to physiological agonists by mobilizing Ca2+ from intracellular InsP3-sensitive stores.