Human Reproduction, Vol. 8, No. 5, pp. 759-763, 1993
© 1993 European Society of Human Reproduction and Embryology
other |
Progesterone antagonist RU 486 accommodates but does not induce labour and delivery in primates
1Laboratoire de Biologie de la Reproduction, Histologie, Embryologie, Cytogénétique, Centre Hospitalier de Bicêtre Paris 2Division of Reproductive Endocrinology and Infertility, Department of Ob/Gyn, Georgetown University School of Medicine 3800 Reservoir Road, Washington, DC, USA 3Israel Institute of Technology, Ramban Medical Centre Haifa, Bat Galim, Israel 4Reproductive Biochemistry and Immunology, Department of Obstetrics and Gynaecology, Royal North Shore Hospital St Leonard, Australia 5Roussel-UCLAF 102, 111 route de Noisy, Romainville 6INSERM, Unite 33, Hôpital de Bicêtre Paris, France 7The Jones Institute for Reproductive Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School 601 Colley Avenue, Norfolk, VA 23507, USA
Correspondence: 8To whom correspondence should be addressed
The hormonal mechanisms of parturition in primates remain controversial. Even so, the well-known decrease of plasma progesterone concentration near term is considered by many as the ‘labour inducer’. The progesterone antagonist RU 486, which blocks progesterone activity at the cellular receptor level, appears to be a useful hormonal tool by which to study this tissue. Here, we tested its capacity to induce labour and delivery. A total of 23 Cynomolgus monkeys (Macaca fascicularis), within 9–17 days of expected term, were assigned to four different protocols to study various doses, routes and regimens of RU 486 administration. Observations included uterine contractile patterns, pharmacokinetics of RU 486 in plasma and passage of RU 486 into breast milk. None of the protocols tested successfully induced labour resulting in vaginal delivery within 24 h. Instead, the data demonstrate that blockade of progesterone activity by the progesterone antagonist was not sufficient by itself to achieve parturition in these primates. Uterine myometrial contractile activity under RU 486 exposure was not sufficient to induce labour and delivery. Moreover, the progesterone antagonist concentration in breast milk was very low, indicating little passage to suckling newborn infants.
Key words: anti-progestins/delivery/labour/primate parturition
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  R. A. Word, C. P. Landrum, B. C. Timmons, S. G. Young, and M. S. Mahendroo Transgene Insertion on Mouse Chromosome 6 Impairs Function of the Uterine Cervix and Causes Failure of Parturition Biol Reprod, November 1, 2005; 73(5): 1046 - 1056. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. L. Casey, J. Smith, G. Alsabrook, and P. C. MacDonald Activation of Adenylyl Cyclase in Human Myometrial Smooth Muscle Cells by Neuropeptides J. Clin. Endocrinol. Metab., September 1, 1997; 82(9): 3087 - 3092. [Abstract] [Full Text] [PDF]
|
|