Progesterone inhibits capacitative Ca2+ entry in Jurkat T lymphocytes by a membrane delimited mechanism, independently of plasma membrane depolarization.
Cell Calcium
; 36(2): 175-80, 2004 Aug.
Article
em En
| MEDLINE
| ID: mdl-15193865
ABSTRACT
The non-genomic inhibitory effect of progesterone on capacitative calcium entry was studied in Jurkat T lymphocytes. Capacitative calcium entry was induced by depleting intracellular calcium stores with thapsigargin and evaluated by a calcium free/calcium readmission protocol, in Fura-2 loaded cells. Progesterone (10-40 microg/ml) inhibited calcium entry and concomitantly depolarized cells, as revealed by measuring the plasma membrane potential with the fluorescent probe bis-oxonol. However, experiments run under depolarizing conditions (i.e. by substituting for Na+ with K+ ions in the medium) revealed that progesterone (10-40 microg/ml) could inhibit capacitative calcium entry independently of plasma membrane depolarization. The direct inhibition of calcium entry by progesterone was (i) reverted by a treatment suitable to remove progesterone bound to cell surface, (ii) apparently related to the extent of membrane bound progesterone (measured radioisotopically), and (iii) specific, in that other related steroid compounds did not inhibit calcium entry.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Progesterona
/
Membrana Celular
/
Cálcio
Tipo de estudo:
Guideline
Limite:
Humans
Idioma:
En
Revista:
Cell Calcium
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Itália