Selective blockers of voltage-gated K+ channels depolarize human T lymphocytes: mechanism of the antiproliferative effect of charybdotoxin.
Year: 1992
Type: article
Abstract: 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.
Authors: R J Leonard, M L Garcia, R S Slaughter, J P Reuben
Institution: Merck & Co., Inc., Rahway, NJ, USA (United States)
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2012462160