Nicotine-evoked cytosolic Ca2+ increase and cell depolarization in capillary endothelial cells of the bovine adrenal medulla
Biol. Res
; 42(1): 111-119, 2009. ilus, tab
Artigo
em Inglês
| LILACS
| ID: lil-519090
Biblioteca responsável:
BR1.1
ABSTRACT
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±0.9 mV; n=23). The increase in cytosolic Ca2+ induced by 10µM ACh was mimicked by the same concentration of nicotine but not by muscarine and was blocked by 100 µM of hexamethonium. On the other hand, the increase in cytosolic Ca2+ could be depressed by nifedipine (0.01 -100 µM) 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.
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
LILACS
Assunto principal:
Canais de Cálcio
/
Receptores Nicotínicos
/
Medula Suprarrenal
/
Citosol
/
Células Endoteliais
/
Nicotina
Limite:
Animais
Idioma:
Inglês
Revista:
Biol. Res
Assunto da revista:
Biologia
Ano de publicação:
2009
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
Chile
Instituição/País de afiliação:
Universidad de Chile/CL
/
Universidad de Valparaiso/CL