Selective blockers of voltage-gated K+ channels depolarize human T lymphocytes: mechanism of the antiproliferative effect of charybdotoxin.
AUTOR(ES)
Leonard, R J
RESUMO
Charybdotoxin (ChTX), a K+ channel blocker, depolarizes human peripheral T lymphocytes and renders them insensitive to activation by mitogen. We observed four types of K+ channels in human T cells: one voltage-activated, and three Ca(2+)-activated. To discern the mechanism by which ChTX depolarizes T cells, we examined the sensitivity of both the voltage-activated and Ca(2+)-activated K+ channels to ChTX and other peptide channel blockers. All four types were blocked by ChTX, whereas noxiustoxin and margatoxin blocked only the voltage-activated channels. All three toxins, however, produced equivalent depolarization in human T cells. We conclude that the membrane potential of resting T cells is set by voltage-activated channels and that blockade of these channels is sufficient to depolarize resting human T cells and prevent activation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=50284Documentos Relacionados
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