Hang Wun Raymond Li1, Su-Bin Liao2, William Shu-Biu Yeung3, Ernest Hung-Yu Ng3, Wai-Sum O4, Pak-Chung Ho3. 1. Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong Centre for Reproduction, Development and Growth, The University of Hong Kong, Hong Kong raymondli@hku.hk. 2. Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong Department of Anatomy, The University of Hong Kong, 21 Sassoon Road, Hong Kong. 3. Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong Centre for Reproduction, Development and Growth, The University of Hong Kong, Hong Kong. 4. Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong Centre for Reproduction, Development and Growth, The University of Hong Kong, Hong Kong Department of Anatomy, The University of Hong Kong, 21 Sassoon Road, Hong Kong.
Abstract
STUDY QUESTION: Do ulipristal acetate (UPA) and mifepristone have an effect on ciliary beat frequency and muscular contractions in the human Fallopian tube? SUMMARY ANSWER: UPA, in resemblance to mifepristone, inhibits ciliary beat and muscular contraction of the human Fallopian tube, probably through an agonistic effect on the tubal progesterone receptor. WHAT IS KNOWN ALREADY: UPA, like mifepristone, acts as an emergency contraceptive mainly by inhibiting ovulation. Little is known about its effects on tubal function. STUDY DESIGN, SIZE, DURATION: This was an in vitro experimental study using Fallopian tube samples collected from 11 women undergoing hysterectomy for benign non-tubal gynaecological conditions. PARTICIPANTS/MATERIALS, SETTING, METHODS: The tubal epithelium and longitudinal smooth muscle fibres were isolated, cultured and treated with UPA at graded concentrations of 0, 20, 200 and 2000 ng/ml, and mifepristone at graded concentrations of 0, 300, 3000 and 30 000 ng/ml, respectively. After treatment, ciliary beat frequency was determined using a photometric method. Basal tone, amplitude and frequency of muscular contraction were recorded through a force transducer. The mRNA expression of progesterone receptor (total and PR-B isoform), glycodelin and adrenomedullin were determined by real-time quantitative PCR. MAIN RESULTS AND THE ROLE OF CHANCE: There was an overall dose-dependent suppressive effect on ciliary beat frequency (P < 0.0001) after treatment with UPA at all concentrations and with mifepristone at 3000 ng/ml or above. The basal tone, amplitude and frequency of muscular contractions were significantly reduced (P < 0.05) after treatment with UPA at 200 ng/ml or above, and with mifepristone at 3000 ng/ml or above. UPA treatment at 200 ng/ml or above significantly up-regulated the mRNA expression of progesterone receptor and glycodelin and down-regulated the mRNA expression of adrenomedullin in Fallopian tube tissue (P < 0.05). LIMITATIONS, REASONS FOR CAUTION: Whether or not the tubal effect may translate into additional mechanisms for contraceptive action in vivo is uncertain. WIDER IMPLICATIONS OF THE FINDINGS: The clinical relevance of UPA with regard to contraceptive activity is worthy of further exploration. STUDY FUNDING/COMPETING INTERESTS: The study was supported by a Seed Fund from the Centre of Reproduction, Development and Growth, Faculty of Medicine, the University of Hong Kong. All authors have no competing interest to declare.
STUDY QUESTION: Do ulipristal acetate (UPA) and mifepristone have an effect on ciliary beat frequency and muscular contractions in the human Fallopian tube? SUMMARY ANSWER: UPA, in resemblance to mifepristone, inhibits ciliary beat and muscular contraction of the human Fallopian tube, probably through an agonistic effect on the tubal progesterone receptor. WHAT IS KNOWN ALREADY: UPA, like mifepristone, acts as an emergency contraceptive mainly by inhibiting ovulation. Little is known about its effects on tubal function. STUDY DESIGN, SIZE, DURATION: This was an in vitro experimental study using Fallopian tube samples collected from 11 women undergoing hysterectomy for benign non-tubal gynaecological conditions. PARTICIPANTS/MATERIALS, SETTING, METHODS: The tubal epithelium and longitudinal smooth muscle fibres were isolated, cultured and treated with UPA at graded concentrations of 0, 20, 200 and 2000 ng/ml, and mifepristone at graded concentrations of 0, 300, 3000 and 30 000 ng/ml, respectively. After treatment, ciliary beat frequency was determined using a photometric method. Basal tone, amplitude and frequency of muscular contraction were recorded through a force transducer. The mRNA expression of progesterone receptor (total and PR-B isoform), glycodelin and adrenomedullin were determined by real-time quantitative PCR. MAIN RESULTS AND THE ROLE OF CHANCE: There was an overall dose-dependent suppressive effect on ciliary beat frequency (P < 0.0001) after treatment with UPA at all concentrations and with mifepristone at 3000 ng/ml or above. The basal tone, amplitude and frequency of muscular contractions were significantly reduced (P < 0.05) after treatment with UPA at 200 ng/ml or above, and with mifepristone at 3000 ng/ml or above. UPA treatment at 200 ng/ml or above significantly up-regulated the mRNA expression of progesterone receptor and glycodelin and down-regulated the mRNA expression of adrenomedullin in Fallopian tube tissue (P < 0.05). LIMITATIONS, REASONS FOR CAUTION: Whether or not the tubal effect may translate into additional mechanisms for contraceptive action in vivo is uncertain. WIDER IMPLICATIONS OF THE FINDINGS: The clinical relevance of UPA with regard to contraceptive activity is worthy of further exploration. STUDY FUNDING/COMPETING INTERESTS: The study was supported by a Seed Fund from the Centre of Reproduction, Development and Growth, Faculty of Medicine, the University of Hong Kong. All authors have no competing interest to declare.