Voltage-dependent ion channels on human basophils: do they exist?
Immunol Lett
; 46(1-2): 81-3, 1995 May.
Article
em En
| MEDLINE
| ID: mdl-7590933
ABSTRACT
The presence of voltage-dependent ion channels (particularly Ca2+ channels) on the surface of 'non excitable' cells such as human basophils is a matter of debate. Indeed, in basophils, Ca2+ entry or mobilization is not sufficient by itself to trigger secretion, although enhanced cytosolic Ca2+ concentration increases it. In order to address this question, we used a two-signal model and we report here experiments which suggest the presence of voltage-dependent structures directly or indirectly linked to membrane Ca2+ pathways. Indeed, it is known that, in the presence of PMA at threshold concentration (1st signal), elevation of cytosolic Ca2+ (2nd signal) induces histamine release. We observed that a depolarizing external solution (high K+) induced a Ca(2+)-dependent release of histamine from PMA-treated human basophils. High K+ alone did not induce histamine release. Although the voltage-sensitive component and the physiological relevance of this mechanism remain to be defined, these results suggest that this voltage-dependent Ca2+ influx in the human basophil could contribute to the up-regulation of histamine release.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Basófilos
/
Ativação do Canal Iônico
/
Canais Iônicos
Limite:
Humans
Idioma:
En
Revista:
Immunol Lett
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
França