%0 Journal Article
%T Nicotine-evoked cytosolic Ca2+ increase and cell depolarization in capillary endothelial cells of the bovine adrenal medulla
%A RA¨²L VINET
%A MAGDALENA CORT¨¦S
%A MARIO LUXORO
%A MARCO A DELPIANO
%J Biological Research
%D 2009
%I Sociedad de Biolog¨ªa de Chile
%X Endothelial cells are directly involved in many functions of the cardiovascular system by regulating blood flow and blood pressure through Ca2+ dependent exocitosis of vasoactive compounds. Using the Ca2+ indicator Fluo-3 and the patch-clamp technique, we show that bovine adrenal medulla capillary endothelial cells (B AMCECs) respond to acetylcholine (ACh) with a cytosolic Ca2+ increase and depolarization of the membrane potential (20.3¡À0.9 mV; n=23). The increase in cytosolic Ca2+ induced by 10¦ÌM ACh was mimicked by the same concentration of nicotine but not by muscarine and was blocked by 100 ¦ÌM of hexamethonium. On the other hand, the increase in cytosolic Ca2+ could be depressed by nifedipine (0.01 -100 ¦ÌM) or withdrawal of extracellular Ca2+. Taken together, these results give evidence for functional nicotinic receptors (nAChRs) in capillary endothelial cells of the adrenal medulla. It suggests that nAChRs in B AMCECs may be involved in the regulation of the adrenal gland's microcirculation by depolarizing the membrane potential, leading to the opening of voltage-activated Ca2+ channels, influx of external Ca2+ and liberation of vasoactive compounds.
%K capillary
%K endothelial cells
%K intracellular Ca2+
%K nicotinic receptor
%K voltage-activated Ca2+ channels
%U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602009000100012