Abstract
1. 1. The effects of catecholestrogens 2-hydroxyestradiol (2-OH E 2, 0.6–30 μM), 4-hydroxy-estradiol (4-OH E 2, 1–30 μM) and 2-methoxyestradiol (2-MeO E 2, 0.6–30 μM) on rat uterine contraction induced by KCI (60 mM), have been assayed. 2. 2. All drugs assayed relaxed the tonic-contraction induced by KCI in a concentration-dependent way. The EC 50s were: 4.4 ± 0.5, 4.2 ± 0.3 and 8.5 ± 0.7 μM for 2-MeO E 2, 2-OH E 2 and 4-OH E 2, respectively. This relaxing effect was counteracted by CaCl 2 (1–10 mM) but not by the calcium channel agonist Bay k 8644 (1 nM-1 μM). 3. 3. The effect of 2-MeO E 2 is not modified by propranolol (1 μM), cycloheximide (35 μM), actinomycin D (4 μM), α-difluoromethyl-ornithine (10 μM) or genistein (10 μM). Not did cycloheximide (35 μM) or actinomycin D (4 μM) modify the relaxing effect of 2-OH E 2 and 4-OH E 2. Propranolol (1 μM) significantly increased the effect of 4-OH E 2 but not the effect of 2-OH E 2. 4. 4. Our results suggest that the relaxing effect of catecholestrogens in the rat uterus is a non-genomic effect and could be related to inhibition of extracellular calcium entry.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
