A R Fuchs1, O Behrens, H C Liu. 1. Department of Obstetrics and Gynecology, Cornell University Medical College, New York, NY 10021.
Abstract
OBJECTIVES: Our purpose was to determine whether plasma oxytocin concentrations show a daily rhythm. STUDY DESIGN: Ten women between 37 and 39 weeks of gestation volunteered for the study. They were admitted 1 to 2 days before the experiment. Three blood samples were taken with 2-minute intervals each time, at 8 AM, 4 PM, and 12 midnight. Oxytocin, 17 beta-estradiol, progesterone, and cortisol were measured by radioimmunoassay with highly specific antibodies. Statistical analysis of variance by Friedman's test was followed by multiple range testing, and p < 0.05 was considered significant. RESULTS: Significant daily rhythm was found for plasma cortisol, progesterone, and oxytocin and for the estradiol/progesterone ratio. Oxytocin showed a nocturnal peak and a strong negative correlation with the estradiol/progesterone ratio. CONCLUSIONS: The daily rhythm in plasma oxytocin parallels the rhythm in uterine activity (shown by others), suggesting a causal relationship between the two. Both may in turn be related to the ratio of circulating estradiol and progesterone.
OBJECTIVES: Our purpose was to determine whether plasma oxytocin concentrations show a daily rhythm. STUDY DESIGN: Ten women between 37 and 39 weeks of gestation volunteered for the study. They were admitted 1 to 2 days before the experiment. Three blood samples were taken with 2-minute intervals each time, at 8 AM, 4 PM, and 12 midnight. Oxytocin, 17 beta-estradiol, progesterone, and cortisol were measured by radioimmunoassay with highly specific antibodies. Statistical analysis of variance by Friedman's test was followed by multiple range testing, and p < 0.05 was considered significant. RESULTS: Significant daily rhythm was found for plasma cortisol, progesterone, and oxytocin and for the estradiol/progesterone ratio. Oxytocin showed a nocturnal peak and a strong negative correlation with the estradiol/progesterone ratio. CONCLUSIONS: The daily rhythm in plasma oxytocin parallels the rhythm in uterine activity (shown by others), suggesting a causal relationship between the two. Both may in turn be related to the ratio of circulating estradiol and progesterone.
Authors: Miguel Angel Luque-Fernandez; Cande V Ananth; Sixto E Sanchez; Chun-fang Qiu; Sonia Hernandez-Diaz; Unnur Valdimarsdottir; Bizu Gelaye; Michelle A Williams Journal: Ann Epidemiol Date: 2014-12 Impact factor: 3.797
Authors: Pei F Lai; Kaiyu Lei; Xiaoyu Zhan; Gavin Sooranna; Jonathan K H Li; Ektoras X Georgiou; Ananya Das; Natasha Singh; Qiye Li; Zachary Stanfield; Guojie Zhang; Rachel M Tribe; Sam Mesiano; Mark R Johnson Journal: PLoS One Date: 2021-11-19 Impact factor: 3.240