Differential effects of progesterone and 17beta-estradiol on the Ca(2+) entry induced by thapsigargin and endothelin-1 in in situ endothelial cells.
The effects of progesterone and 17beta-estradiol on Ca(2+) 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 [Ca(2+)](i) elevation (IC(50)=33.9 microM, n=4), while 17beta-estradiol added a transient [Ca(2+)](i) elevation. Progesterone and 17beta-estradiol had no significant effect on the thapsigargin-induced [Ca(2+)](i) elevations in the absence of extracellular Ca(2+). A Mn(2+)-induced decline of fluorescent intensity at 360 nm excitation was accelerated by thapsigargin. This acceleration was completely reversed by progesterone, but not by 17beta-estradiol. Progesterone inhibited, and 17beta-estradiol enhanced the endothelin-1 (ET-1)-induced [Ca(2+)](i) elevation, while both had no effect on the ET-1-induced Ca(2+) release observed in the absence of extracellular Ca(2+) or in the pertussis toxin-treated strips. Progesterone and 17beta-estradiol thus had different effects on Ca(2+) signaling, especially on Ca(2+) influx, in endothelial cells.
Toshima
J Y
JY
Hirano
K
K
Nishimura
J
J
Nakano
H
H
Kanaide
H
H
D000818:Animals; D001021:Aortic Valve; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid; D019332:Endothelin-1 / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D005470:Fluorometry; D016257:Fura-2; D066298:In Vitro Techniques; D008345:Manganese / Q000378:metabolism; D011374:Progesterone / Q000494:pharmacology*; D013552:Swine; D019284:Thapsigargin / Q000494:pharmacology
D019332:Endothelin-1; D008345:Manganese; D011374:Progesterone; D004958:Estradiol; D004533:Egtazic Acid; D019284:Thapsigargin; D002118:Calcium; D016257:Fura-2