Effects of antiandrogens and progesterone on isolated rat uterus.
1. The effect of progesterone (P, 6 x 10(-6)-6 x 10(-5) M) and the antiandrogens cyproterone acetate (CPA, 10(-7)-10(-5) M), flutamide (F, 10(-6)-6 x 10(-5) M) and spironolactone (S, 10(-6)-6 x 10(-5) M) on the KCl-induced tonic contraction of the isolated rat uterus have been assayed. 2. The antiandrogens relaxed, in a dose-dependent way, the KCl-induced contraction (EC50, 2.804 +/- 0.506 x 10(-6); 1.671 +/- 0.308 x 10(-5); and 3.042 +/- 0.14 x 10(-5) M, respectively for CPA, S and F). P also relaxed the KCl-induced contraction (EC50, 2.436 +/- 0.524 x 10(-5) M). 3. CaCl2 (0.1-10 mM) counteracted the relaxing effect of CPA, S, F, and P, respectively, up to 100, 80.63, 60.66 and 90.57%. 4. The 17-OH-progesterone derivative CPA, but not S or F, reduces at small doses (6 x 10(-8) M), but not at higher concentrations (6 x 10(-7)-6 x 10(-6) M), the relaxing effect of progesterone.
Sanchez Aparício
J A
JA
Laboratorio de Farmacología, Departamento de Medicina, Facultad de Medicina, Oviedo, Spain.
Cantabrana
B
B
Hidalgo
A
A
D000726:Androgen Antagonists / Q000494:pharmacology*; D000818:Animals; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D011189:Potassium Chloride / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014590:Uterine Contraction / Q000187:drug effects; D014599:Uterus / Q000187:drug effects*
D000726:Androgen Antagonists; D011374:Progesterone; D011189:Potassium Chloride