Abstract # 20:

Scheduled for Thursday, August 17, 2006 11:45 AM-12:00 PM: Session 2 (Regency East #2) Oral Presentation

Expression and function of corticotropin-releasing hormone (CRH) in anthropoid primate placenta.

M. L. Power1,2, M. E. Bowman3, R. Smith3, D. G. Layne4, T. E. Ziegler5, S. D. Tardif4 and J. Schulkin1,6
1American College of Obstetricians and Gynecologists, Research Department, Washington, DC 20024, USA, 2Smithsonian National Zoological Park, Washington DC 20008, USA, 3Mothers and Babies Research Centre, Hunter Medical Research Institute, John Hunter Hospital, Newcastle, NSW, Australia , 4Southwest National Primate Research Center, San Antonio, TX 78245-0549, USA, 5Department of Psychology and National Primate Research Center, University of Wisconsin, Madison WI, USA, 6Department of Physiology and Biophysics, Georgetown University, School of Medicine, Washington DC, USA
     Corticotropin-releasing hormone (CRH) is a 41 amino acid neuropeptide expressed in the brain and also is widely expressed throughout the body. CRH is expressed in much of the female reproductive tract. An apparently unique reproductive function for CRH has arisen in anthropoid primates: placental expression of CRH. There appear to be at least two patterns of placental CRH expression during gestation in anthropoids. We found that the pattern expressed by common marmosets (Callithrix jacchus) was similar to the pattern previously described by others in baboons (Papio anubis and P. hamadryas), with a peak of CRH expression in early-mid gestation. The timing of the initiation of CRH expression in common marmosets (50 – 55 days gestation) coincides with the initiation of rapid growth and development of placenta and fetuses. Maternal CRH concentration peaked at 70-90 days gestation, and then decreased to about 10% of the peak and remained relatively constant. In apes, represented by humans, chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla), CRH can be detected by the second trimester, and then exponentially increases until parturition. Deviation from the normal pattern of CRH expression is associated with poor pregnancy outcome in both humans and common marmosets. The functional significance of the differences in placental CRH expression between monkeys and apes is not yet understood, but it supports the hypothesis that placental CRH performs multiple roles during gestation.