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 O’Neil, J. S. Articles by Henson, M. C. Search for Related Content PubMed PubMed Citation Articles by O’Neil, J. S. Articles by Henson, M. C.

Regulation of Leptin and Leptin Receptor in Baboon Pregnancy: Effects of Advancing Gestation and Fetectomy¹

Departments of Obstetrics and Gynecology (J.S.O., A.E.G., D.E.E., K.F.S., M.C.H.), Physiology (M.C.H.), and Structural and Cellular Biology (M.C.H.) and Interdisciplinary Program in Molecular and Cellular Biology (J.S.O., A.E.G., D.E.E., M.C.H.), Tulane University Health Sciences Center, New Orleans, Louisiana 70112-2699; Tulane Regional Primate Research Center (M.C.H.), Covington, Louisiana 70433-8915; and Department of Obstetrics and Gynecology and Women’s Health Research Institute of Amarillo, Texas Tech University Health Sciences Center (T.G., V.D.C.), Amarillo, Texas 79106-1797

Address all correspondence and requests for reprints to: Michael C. Henson, Ph.D., Department of Obstetrics and Gynecology (SL11), Tulane University Health Sciences Center, 1430 Tulane Avenue, New Orleans, Louisiana 70112-2699. E-mail: michael.henson{at}tulane.edu

Abstract

Leptin, a product of both adipose tissue and the placental syncytiotrophoblast and a potential regulator of primate conceptus development, increases in the maternal circulation with advancing gestation. This increase may be potentiated by estrogens, which also increase as pregnancy progresses. In the present study adipose tissue was collected from nonpregnant (n = 5) baboons (Papio sp) and in baboons during early (days 58–62; n = 5), mid (days 98–102; n = 5), and late (days 158–162; n = 5) pregnancy (term, 184 days). Additionally, placental estrogen production was inhibited in pregnant baboons by the removal of fetal androgen precursors via fetectomy at midgestation, with tissues collected from fetectomized (n = 5) baboons approximately 60 days later. Leptin, estrogens, and androgens were quantitated in maternal serum by RIA. Leptin (LEP) and leptin receptor (LEP-R_L and LEP-R_S isoforms) messenger ribonucleic acids (mRNAs) were quantitated by competitive RT-PCR, and leptin concentrations were determined by RIA in maternal adipose and placental villous tissues.

Although LEP transcript abundance in adipose tissues was unchanged as a result of pregnancy or with advancing gestation, the leptin protein level was higher (P < 0.02) in pregnant baboons in early gestation than in nonpregnant baboons and increased with gestational age (P < 0.04). Maternal serum estrogens (estradiol and estrone) and androgens (androstenedione and testosterone) were lower (P < 0.0001) in fetectomized baboons than in intact controls. Serum leptin concentrations were unchanged by fetectomy, but the abundance of LEP mRNA transcripts was lower (P < 0.003) in sc adipose tissue and 3-fold higher (P < 0.05) in placenta. Similarly, the leptin protein level declined (P < 0.05) in sc adipose tissue and increased (P < 0.05) in placenta in fetectomized baboons. Although LEP-R_L mRNA levels were unchanged after fetectomy, placental LEP-R_S transcript abundance was lower (P < 0.04) than in pregnancy-intact baboons matched for gestational age. Results suggest that both adipose tissue and the placenta may contribute to maternal hyperleptinemia during normal primate pregnancy. Furthermore, the withdrawal of placental steroids results in the enhanced placental leptin production that is commensurate with a decline in production by sc adipose tissue.

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]

				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]

				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]