The effect of nifedipine-an antagonist of L-type calcium (Ca(2+)) channels-on capacitative Ca(2+) entry (CCE) was studied in Jurkat T lymphocytes. CCE was induced by a variety of treatments each of which depleted intracellular Call stores. Cells were treated with thapsigargin, ionomycin, anti-CD3 antibodies, and phyto-haemagglutinin, or pre-incubated in a Ca(2+)-free medium. Activity of CCE was evaluated with a Ca(2+)-free/Ca(2+)-readmission protocol, in Fluo-3 pre-loaded cells. Nifedipine inhibited CCE in a dose-dependent manner. CCE inhibition was not due to non-specific effects on K(+) channels. Nifedipine, did not induce any membrane depolarization, as revealed by measurements of the plasma membrane potential with the fluorescent probe bis-oxonol. Moreover, experiments done under depolarizing conditions (i.e. by substituting Na(+) with K(+) ions in the medium) revealed that nifedipine could inhibit capacitative Ca(2+) entry independently of plasma membrane depolarization. We also demonstrated the presence in our Jurkat T-cells of transcripts for Ca(V)1.3 (alpha(1D)) and Ca(V)1.4 (alpha(1F)) L-type Ca(2+) channels. Verapamil and diltiazem, two unrelated blockers of L-type Ca(2+) channels, were less inhibitory on CCE. Possible mechanisms by which nifedipine interferes with Ca(2+) entry in these cells are discussed.

Colucci, A., Giunti, R., Senesi, S., Bygrave, F.L., Benedetti, A., Gamberucci, A. (2009). Effect of nifedipine on capacitive calcium entry in Jurkat T lymphocytes. ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 481(1), 80-85 [10.1016/j.abb.2008.10.002].

Effect of nifedipine on capacitive calcium entry in Jurkat T lymphocytes

COLUCCI, A.;GIUNTI, R.;BENEDETTI, A.;GAMBERUCCI, A.
2009-01-01

Abstract

The effect of nifedipine-an antagonist of L-type calcium (Ca(2+)) channels-on capacitative Ca(2+) entry (CCE) was studied in Jurkat T lymphocytes. CCE was induced by a variety of treatments each of which depleted intracellular Call stores. Cells were treated with thapsigargin, ionomycin, anti-CD3 antibodies, and phyto-haemagglutinin, or pre-incubated in a Ca(2+)-free medium. Activity of CCE was evaluated with a Ca(2+)-free/Ca(2+)-readmission protocol, in Fluo-3 pre-loaded cells. Nifedipine inhibited CCE in a dose-dependent manner. CCE inhibition was not due to non-specific effects on K(+) channels. Nifedipine, did not induce any membrane depolarization, as revealed by measurements of the plasma membrane potential with the fluorescent probe bis-oxonol. Moreover, experiments done under depolarizing conditions (i.e. by substituting Na(+) with K(+) ions in the medium) revealed that nifedipine could inhibit capacitative Ca(2+) entry independently of plasma membrane depolarization. We also demonstrated the presence in our Jurkat T-cells of transcripts for Ca(V)1.3 (alpha(1D)) and Ca(V)1.4 (alpha(1F)) L-type Ca(2+) channels. Verapamil and diltiazem, two unrelated blockers of L-type Ca(2+) channels, were less inhibitory on CCE. Possible mechanisms by which nifedipine interferes with Ca(2+) entry in these cells are discussed.
Colucci, A., Giunti, R., Senesi, S., Bygrave, F.L., Benedetti, A., Gamberucci, A. (2009). Effect of nifedipine on capacitive calcium entry in Jurkat T lymphocytes. ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 481(1), 80-85 [10.1016/j.abb.2008.10.002].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/20226
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