Asunto(s)
Fluorodesoxiglucosa F18 , Neoplasias Gastrointestinales/diagnóstico por imagen , Neoplasias Gastrointestinales/cirugía , Células del Estroma/diagnóstico por imagen , Tomografía Computarizada de Emisión/métodos , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Resultado del TratamientoRESUMEN
In isolated rat peritoneal mast cells, an outwardly rectifying Cl- channel has been described. Influx of Cl- through this Cl- channel (I(Cl-(OR)) causes hyperpolarization, which facilitates Ca2+ currents through store-operated Ca2+ channels. The exocytotic effect of nerve growth factor (NGF) in the presence of lyso-phosphatidylserine strictly depends on the presence of extracellular [Ca2+]o. The aim of the present study was to assess the importance of I(Cl-(OR)) for exocytosis induced by NGF/lyso-phosphatidylserine. Therefore, we investigated the effects on NGF/lyso-phosphatidylserine-induced exocytosis of [3H]5-hydroxytryptamine ([3H]5-HT) in rat peritoneal mast cells: (a) of two inhibitors of I(Cl-(OR)) (4,4'-diisothiocyanatostilbene2,2'-disulfonic acid [DIDS] and diethylstilbestrol), and (b) of replacement of extracellular Cl- by methylsulfate. Additionally, whole-cell patch-clamp experiments (nystatin-perforated patch) were performed. Diethylstibestrol and DIDS, in concentrations sufficient to abolish the I(Cl-(OR)) (10 microM) and the replacement of (Cl-)o by methylsulfate, were ineffective in impairing the NGF/lyso-phosphatidylserine-induced [3H]5-HT-release. These findings argue against a role of outwardly rectifying Cl- channels in exocytosis induced by NGF/lyso-phosphatidylserine in rat peritoneal mast cells.