The effects of progesterone and 17β-estradiol on Ca2+ signaling in in situ endothelial cells were investigated using front-surface fluorometry of fura-2-loaded strips of porcine aortic valve. Progesterone inhibited the thapsigargin-induced sustained [Ca2+](i) elevation (IC50 = 33.9 μM, n = 4), while 17β-estradiol added a transient [Ca2+](i) elevation. Progesterone and 17β-estradiol had no significant effect on the thapsigargin-induced [Ca2+](i) elevations in the absence of extracellular Ca2+. A Mn2+-induced decline of fluorescent intensity at 360 nm excitation was accelerated by thapsigargin. This acceleration was completely reversed by progesterone, but not by 17β-estradiol. Progesterone inhibited, and 17β-estradiol enhanced the endothelin-1 (ET-1)-induced [Ca2+](i) elevation, while both had no effect on the ET-1-induced Ca2+ release observed in the absence of extracellular Ca2+ or in the pertussis toxin-treated strips. Progesterone and 17β-estradiol thus had different effects on Ca2+ signaling, especially on Ca2+ influx, in endothelial cells. (C) 2000 Elsevier Science B.V.
|ジャーナル||Biochimica et Biophysica Acta - Molecular Cell Research|
|出版ステータス||Published - 2000 12月 11|
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