Estrogen and antiestrogen non-genomic effect in rat uterus contraction in calcium-free solution.
1. The effects of estrogens estradiol (E2, 10(-6)-10(-4) M) and diethylstilbestrol (DES, 10(-6)-10(-4) M) and the antiestrogens nafoxidine (N, 10(-6)-10(-4) M), tamoxifen (T, 10(-6)-6 x 10(-4) M), tamoxifen ethyl bromide (TEB, 10(-4) M) and ICI 164,384 (ICI, 10(-5) M) on tonic contractions induced by oxytocin (2 x 10(-8) M) or vanadate (3 x 10(-4) M) in rat uterus incubated in calcium-free EDTA treated solution have been assayed. 2. E2 and DES relaxed the tonic contraction induced by oxytocin in a dose dependent way (EC50: 1.11 +/- 0.01 x 10(-4) M and 1.5 +/- 0.07 x 10(-5) M). The vanadate-induced contraction only was relaxed with DES (57.62 +/- 2.38% at 10(-3) M). 3. The effect of DES on oxytocin contraction was unmodified by the protein synthesis inhibitor cycloheximide (10 micrograms/ml) and by the cyclooxygenase inhibitor indomethacin (3 x 10(-6) M), but enhanced by the intracellular calcium release inhibitor TMB-8 (10(-5) M). The antiestrogen tamoxifen (3 x 10(-5) M) promotes the relaxing effect of DES. 4. The antiestrogens N, and T, but not ICI, relaxed the oxytocin-induced contraction (EC50: 4.51 +/- 0.43 x 10(-5) M and 2.27 +/- 0.05 x 10(-4) M). TEB (10(-4) M) produces a relaxation of 74.5 +/- 2.11%. The vanadate contraction is also relaxed by T (EC50: 6.03 +/- 0.04 x 10(-4) M). 5. The effect of T on oxytocin contraction was unmodified with cycloheximide or TMB-8 but decreased with indomethacin.
Fernandez
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A
Departamento de Medicina, Facultad de Medicina, Universidad de Oviedo, Spain.
Cantabrana
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B
Hidalgo
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A
D000818:Animals; D002118:Calcium / Q000502:physiology*; D004965:Estrogen Antagonists / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D010121:Oxytocin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014590:Uterine Contraction / Q000187:drug effects*; D014638:Vanadates / Q000494:pharmacology
D004965:Estrogen Antagonists; D004967:Estrogens; D014638:Vanadates; D010121:Oxytocin; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D002118:Calcium; D007213:Indomethacin