K+ channels and the microglial respiratory burst.
Am J Physiol Cell Physiol
; 280(4): C796-806, 2001 Apr.
Article
em En
| MEDLINE
| ID: mdl-11245596
ABSTRACT
Microglial activation following central nervous system damage or disease often culminates in a respiratory burst that is necessary for antimicrobial function, but, paradoxically, can damage bystander cells. We show that several K+ channels are expressed and play a role in the respiratory burst of cultured rat microglia. Three pharmacologically separable K+ currents had properties of Kv1.3 and the Ca2+/calmodulin-gated channels, SK2, SK3, and SK4. mRNA was detected for Kv1.3, Kv1.5, SK2, and/or SK3, and SK4. Protein was detected for Kv1.3, Kv1.5, and SK3 (selective SK2 and SK4 antibodies not available). No Kv1.5-like current was detected, and confocal immunofluorescence showed the protein to be subcellular, in contrast to the robust membrane localization of Kv1.3. To determine whether any of these channels play a role in microglial activation, a respiratory burst was stimulated with phorbol 12-myristate 13-acetate and measured using a single cell, fluorescence-based dihydrorhodamine 123 assay. The respiratory burst was markedly inhibited by blockers of SK2 (apamin) and SK4 channels (clotrimazole and charybdotoxin), and to a lesser extent, by the potent Kv1.3 blocker agitoxin-2.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Canais de Potássio
/
Explosão Respiratória
/
Microglia
/
Canais de Potássio Cálcio-Ativados
/
Canais de Potássio de Abertura Dependente da Tensão da Membrana
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol Cell Physiol
Ano de publicação:
2001
Tipo de documento:
Article