1. In vitroresponsiveness of human post-menopausal myometrium to endothelin-1 and ovarian steroids
- Author
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Domali, E., Molyvdas, P., and Messinis, I.
- Abstract
It has been shown in vitrothat endothelin 1 (ET1) differentially affects the human myometrial contractility according to the hormonal profile of women. Our purpose was to test the hypothesis that ovarian steroids influence the ET1-induced myometrial contractility. We performed three types of experiments. Myometrial tissues were exposed to 17β-oestradiol (E), progesterone (P), E plus P (E+P) in concentrations 10t−10M, 10−8M, 10−7M, 10t−6M and 10−4M (Type I), ET1 in concentrations 10t−10M, 10−9M, 10−8M, 10−7M and 10t−6M (Type II) and E+ET1, P+ET1 and E+P+ET1 in concentrations ranging from 10−10M to 10−6M (Type III). Tissue exposure to E, P and E+P did not significantly alter the pattern of spontaneous myometrial motility. ET1 (10−6M) induced a sustained long-lasting contraction, the initial part of which lasted 34±4 min, elevating the initial baseline by 190±20%. This was followed by ripples of gradually increasing amplitude with no regular contractions up to the end of the period of observation (120 min). Addition of P or E+P to ET1 markedly restricted (p<0.05) the elevation of initial baseline (P+ET1: 68±8%, P+E+ET1: 67±8%), and significantly shortened (p<0.01) the duration of the alterations (P+ET1: 21±3 min, P+E+ET1: 26±3 min). These results demonstrate the lack of any significant effect of E and P or their combinations on the pattern of spontaneous myometrial motility in post-menopausal women. However, P alone or in combination with E exerted an inhibitory action on ET1-induced contractility on human post-menopausal myometrium. The physiological significance of these findings remains to be clarified.
- Published
- 2005
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