This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Henson, M. C. Articles by Shi, W. Search for Related Content PubMed PubMed Citation Articles by Henson, M. C. Articles by Shi, W.

Serum Leptin Concentrations and Expression of Leptin Transcripts in Placental Trophoblast with Advancing Baboon Pregnancy¹

Departments of Obstetrics/Gynecology (M.C.H., J.S.O., K.F.S., W.S.), Physiology (M.C.H., W.S.), and Anatomy (M.C.H.) and the Interdisciplinary Program in Molecular and Cellular Biology (M.C.H., J.S.O., A.E.G.), Tulane University School of Medicine, New Orleans, Louisiana 70112-2699; Tulane Regional Primate Research Center (M.C.H.), Covington, Louisiana 70433-8915; and the Department of Obstetrics/Gynecology, Texas Tech University Health Sciences Center (V.D.C., T.G.), Amarillo, Texas 79106-1797

Address all correspondence and requests for reprints to: Michael C. Henson, Ph.D., Department of Obstetrics/Gynecology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112-2699. E-mail: michael.henson{at}tulane.edu

Leptin is a polypeptide hormone originally thought to be produced exclusively by adipocytes. Recently, however, both leptin messenger ribonucleic acid (mRNA) and leptin protein were identified in human placental trophoblast cells, suggesting a potential role in primate pregnancy. In the present study, venous blood samples were collected at 5-day intervals during gestation from baboons (Papio sp), an established model for the study of human pregnancy, as well as from nonpregnant baboons, and leptin concentrations were determined by RIA. Additionally, placental villous tissue was collected upon cesarean delivery at early (days 60–62; n = 5), mid (days 98–102; n = 5), and late (days 159–167; n = 5) gestation (term = 184 days), and leptin mRNA was quantitated by competitive RT-PCR. Finally, in situ hybridization was employed to localize transcripts to specific placental cell types. Results determined that maternal leptin levels (mean ± SEM), which were dramatically greater (P < 0.01) than those in nonpregnant cycling baboons (1.4 ± 0.1 ng/mL), increased (P < 0.005) with gestational age from 63.6 ± 10.4 ng/mL on day 60 of gestation to 157.8 ± 16.1 near term. Levels declined to those found in cycling baboons by 15 days postdelivery. In contrast to maternal leptin concentrations, placental leptin mRNA decreased (P < 0.02) with advancing pregnancy, as transcript abundance declined approximately 8-fold from early to late gestation. Maternal peripheral leptin concentrations were positively correlated (r = 0.66; P < 0.001) whereas placental leptin mRNA levels were negatively correlated (r = -0.64; P < 0.01) with gestational age. Expression of leptin mRNA transcripts, as evidenced by RT-PCR in villous tissue, was localized principally within syncytiotrophoblast by in situ hybridization.

In summary, changes in maternal peripheral leptin concentrations and placental leptin mRNA abundance that occur commensurate with advancing gestational age may imply evolving roles for the polypeptide with advancing primate pregnancy. In this capacity, localization of leptin transcripts within the baboon syncytiotrophoblast suggests the potential for autocrine or paracrine interactions within this endocrinologically active tissue. Finally, both the similarities in leptin ontogeny in baboon and human pregnancy and the singular enhancement of maternal leptin levels inherent throughout baboon gestation emphasize the potential of this nonhuman primate model for the study of leptin action in the maternal-fetoplacental unit.

This article has been cited by other articles:

				M. C. Henson and V. D. Castracane Leptin in Pregnancy: An Update Biol Reprod, February 1, 2006; 74(2): 218 - 229. [Abstract] [Full Text] [PDF]

				V. D. Castracane, A. G. Hendrickx, and M. C. Henson Serum Leptin in Nonpregnant and Pregnant Women and in Old and New World Nonhuman Primates Experimental Biology and Medicine, April 1, 2005; 230(4): 251 - 254. [Abstract] [Full Text] [PDF]

				L. C. Schulz and E. P. Widmaier The Effect of Leptin on Mouse Trophoblast Cell Invasion Biol Reprod, December 1, 2004; 71(6): 1963 - 1967. [Abstract] [Full Text] [PDF]

				D. E. Edwards, R. P. Bohm Jr, J. Purcell, M. S. Ratterree, K. F. Swan, V. D. Castracane, and M. C. Henson Two Isoforms of the Leptin Receptor Are Enhanced in Pregnancy-Specific Tissues and Soluble Leptin Receptor Is Enhanced in Maternal Serum with Advancing Gestation in the Baboon Biol Reprod, November 1, 2004; 71(5): 1746 - 1752. [Abstract] [Full Text] [PDF]

				B.S.J. Yuen, P.C. Owens, M.E. Symonds, D.H. Keisler, J.R. McFarlane, K.G. Kauter, and I.C. McMillen Effects of Leptin on Fetal Plasma Adrenocorticotropic Hormone and Cortisol Concentrations and the Timing of Parturition in the Sheep Biol Reprod, June 1, 2004; 70(6): 1650 - 1657. [Abstract] [Full Text] [PDF]

				M C Henson, K F Swan, D E Edwards, G W Hoyle, J Purcell, and V D Castracane Leptin receptor expression in fetal lung increases in late gestation in the baboon: a model for human pregnancy Reproduction, January 1, 2004; 127(1): 87 - 94. [Abstract] [Full Text] [PDF]

				J. Zhao, T. H. Kunz, N. Tumba, L. Clamon Schulz, C. Li, M. Reeves, and E. P. Widmaier Comparative analysis of expression and secretion of placental leptin in mammals Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2003; 285(2): R438 - R446. [Abstract] [Full Text] [PDF]

				A. M. Mistry and D. R. Romsos Intracerebroventricular Leptin Administration Reduces Food Intake in Pregnant and Lactating Mice Experimental Biology and Medicine, September 1, 2002; 227(8): 616 - 619. [Abstract] [Full Text] [PDF]

				R. M. Seeber, J. T. Smith, and B. J. Waddell Plasma Leptin-Binding Activity and Hypothalamic Leptin Receptor Expression During Pregnancy and Lactation in the Rat Biol Reprod, June 1, 2002; 66(6): 1762 - 1767. [Abstract] [Full Text] [PDF]

				R. A. Ehrhardt, A. W. Bell, and Y. R. Boisclair Spatial and developmental regulation of leptin in fetal sheep Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2002; 282(6): R1628 - R1635. [Abstract] [Full Text] [PDF]

				M. Groschl, M. Rauh, R. Wagner, W. Neuhuber, M. Metzler, G. Tamguney, J. Zenk, E. Schoof, H. G. Dorr, W. F. Blum, et al. Identification of Leptin in Human Saliva J. Clin. Endocrinol. Metab., November 1, 2001; 86(11): 5234 - 5239. [Abstract] [Full Text] [PDF]

				W. A. Banks, J. E. Phillips-Conroy, C. J. Jolly, and J. E. Morley Serum Leptin Levels in Wild and Captive Populations of Baboons (Papio): Implications for the Ancestral Role of Leptin J. Clin. Endocrinol. Metab., September 1, 2001; 86(9): 4315 - 4320. [Abstract] [Full Text] [PDF]

				J. S. O'Neil, A. E. Green, D. E. Edwards, K. F. Swan, T. Gimpel, V. D. Castracane, and M. C. Henson Regulation of Leptin and Leptin Receptor in Baboon Pregnancy: Effects of Advancing Gestation and Fetectomy J. Clin. Endocrinol. Metab., June 1, 2001; 86(6): 2518 - 2524. [Abstract] [Full Text] [PDF]

				M. C. Henson and V. D. Castracane Leptin in Pregnancy Biol Reprod, November 1, 2000; 63(5): 1219 - 1228. [Abstract] [Full Text]

				N. Kronfeld-Schor, J. Zhao, B. A. Silvia, E. Bicer, P. T. Mathews, R. Urban, S. Zimmerman, T. H. Kunz, and E. P. Widmaier Steroid-Dependent Up-Regulation of Adipose Leptin Secretion In Vitro During Pregnancy in Mice Biol Reprod, July 1, 2000; 63(1): 274 - 280. [Abstract] [Full Text]

				A. E. Green, J. S. O'neil, K. F. Swan, R. P. Bohm Jr., M. S. Ratterree, and M. C. Henson Leptin Receptor Transcripts Are Constitutively Expressed in Placenta and Adipose Tissue with Advancing Baboon Pregnancy Experimental Biology and Medicine, April 1, 2000; 223(4): 362 - 366. [Abstract] [Full Text] [PDF]