Abstract
In 10 chronically instrumented pregnant ewes myometrial electrical activity and intrauterine pressure were measured and plasma levels of 17β-estradiol and progesterone were determined in late pregnancy and during and after labor. Myometrial biopsies were obtained to determine gap junction area. Plasma progesterone levels fell 4 days before delivery, and 17β-estradiol levels rose sharply 12 hours before delivery. Toward delivery the myometrial electrical pattern changed from infrequent bursts of long duration to frequent bursts of short duration, and the active pressure area of the intrauterine pressure cycles, the apparent conduction velocity, and the rate of rise of intrauterine pressure cycles increased associated with the changes in hormone levels. These changes were related to an increase in gap junction area. It is concluded that these results support the hypothesis that changes in concentrations of steroid hormones lead to an increase in myometrial gap junction area, which improves the coordination of contractile activity of the uterus during labor.
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.
