Endocrinology, Vol 122, 78-83, Copyright © 1988 by Endocrine Society

ARTICLES

The regulation of transplacental cortisol-cortisone metabolism by estrogen in pregnant baboons

GJ Pepe, BJ Waddell, SJ Stahl and ED Albrecht
Department of Physiology, Eastern Virginia Medical School, Norfolk 23507.

The present study tests the hypothesis that estrogen regulates the alteration in baboon placental cortisol (F)/cortisone (E) interconversion from preferential reduction (E----F) at midgestation to oxidation (F----E) near term. Five pregnant baboons (Papio anubis) received increasing numbers of 50-mg implants of androstenedione inserted sc at 8-day intervals between days 70 and 100 of gestation (term = day 184) to elevate the production of estrogen. Five animals served as controls at midgestation and received implants containing no steroid, while four baboons were studied near term between days 164-170 of gestation. All animals were bled from a maternal saphenous vein at 2- day intervals, and the serum was assayed for estradiol. On days 100 or 170 of gestation, transuterofetoplacental corticosteroid dynamics were determined by the constant infusion method. Baboons were anesthetized with ketamine and halothane-nitrous oxide and a constant infusion of [3H]F/[14C]E initiated via a maternal saphenous vein. At 60 min, animals were laparotomized and at 70, 80, and 90 min, blood samples were obtained from right and left uterine veins and from a maternal saphenous vein. At 95 min, an incision was made in the uterus, and blood samples were obtained from the umbilical vein and artery. Radiolabeled F and E were extracted from serum and purified by paper chromatography. Maternal serum E2 concentrations (nanograms per ml; mean +/- SE) were greater (P less than 0.01) between days 94 and 100 of gestation in androstenedione-treated baboons (2.4 +/- 0.3) than in untreated animals at midgestation (0.7 +/- 0.2), but lower than those near term (4.5 +/- 1.0). On day 100 of gestation, conversion of E to F across the uterus in control animals (30%) was similar to that of the reverse reaction (23%). In androstenedione-treated baboons at midgestation the conversion of E----F (8%) was lower (P less than 0.05) than the oxidation of F----E (27%) and not different from that in untreated baboons at term (E----F = 13%; F----E = 28%). The dominance of transuterofetoplacental conversion of F----E over the conversion of E----F in term and in androstenedione-treated animals at midgestation was maintained when transfer constants were corrected for fetal metabolic contributions. We conclude that the increase in placental estrogen production induced by androstenedione administration at midgestation alters the pattern of transuterofetoplacental F-E metabolism, supporting the hypothesis that estrogen regulates placental corticosteroid metabolism.

This article has been cited by other articles:

				G. J. Pepe, M. G. Burch, and E. D. Albrecht Developmental Regulation of the Sodium/Hydrogen Ion Exchangers and Their Regulatory Factors in Baboon Placental Syncytiotrophoblast Endocrinology, June 1, 2006; 147(6): 2986 - 2996. [Abstract] [Full Text] [PDF]

				L. Julan, H. Guan, J. P. van Beek, and K. Yang Peroxisome Proliferator-Activated Receptor {delta} Suppresses 11{beta}-Hydroxysteroid Dehydrogenase Type 2 Gene Expression in Human Placental Trophoblast Cells Endocrinology, March 1, 2005; 146(3): 1482 - 1490. [Abstract] [Full Text] [PDF]

				G. J. Pepe, P. L. Ballard, and E. D. Albrecht Fetal Lung Maturation in Estrogen-Deprived Baboons J. Clin. Endocrinol. Metab., January 1, 2003; 88(1): 471 - 477. [Abstract] [Full Text] [PDF]

				A. Thompson, V.K.M. Han, and K. Yang Spatial and Temporal Patterns of Expression of 11{beta}-Hydroxysteroid Dehydrogenase Types 1 and 2 Messenger RNA and Glucocorticoid Receptor Protein in the Murine Placenta and Uterus During Late Pregnancy Biol Reprod, December 1, 2002; 67(6): 1708 - 1718. [Abstract] [Full Text] [PDF]

				G. J. Pepe, M. G. Burch, and E. D. Albrecht Estrogen Regulates 11{beta}-Hydroxysteroid Dehydrogenase-1 and -2 Localization in Placental Syncytiotrophoblast in the Second Half of Primate Pregnancy Endocrinology, October 1, 2001; 142(10): 4496 - 4503. [Abstract] [Full Text] [PDF]

				G. J. Pepe, M. G. Burch, and E. D. Albrecht Localization and Developmental Regulation of 11{beta}-Hydroxysteroid Dehydrogenase-1 and -2 in the Baboon Syncytiotrophoblast Endocrinology, January 1, 2001; 142(1): 68 - 80. [Abstract] [Full Text] [PDF]

				D.B. Hardy, L.E. Pereria, and K. Yang Prostaglandins and Leukotriene B4 Are Potent Inhibitors of 11ß-Hydroxysteroid Dehydrogenase Type 2 Activity in Human Choriocarcinoma JEG-3 Cells Biol Reprod, July 1, 1999; 61(1): 40 - 45. [Abstract] [Full Text]

				J. Tremblay, D.B. Hardy, L.E. Pereira, and K. Yang Retinoic Acid Stimulates the Expression of 11ß-Hydroxysteroid Dehydrogenase Type 2 in Human Choriocarcinoma JEG-3 Cells Biol Reprod, March 1, 1999; 60(3): 541 - 545. [Abstract] [Full Text]

				P. J. Burton and B. J. Waddell Dual Function of 11ß-Hydroxysteroid Dehydrogenase in Placenta: Modulating Placental Glucocorticoid Passage and Local Steroid Action Biol Reprod, February 1, 1999; 60(2): 234 - 240. [Abstract] [Full Text] [PDF]

				B. J. Waddell, R. Benediktsson, R. W. Brown, and J. R. Seckl Tissue-Specific Messenger Ribonucleic Acid Expression of 11{beta}-Hydroxysteroid Dehydrogenase Types 1 and 2 and the Glucocorticoid Receptor within Rat Placenta Suggests Exquisite Local Control of Glucocorticoid Action Endocrinology, April 1, 1998; 139(4): 1517 - 1523. [Abstract] [Full Text] [PDF]

				M. G. Leavitt, G. W. Aberdeen, M. G. Burch, E. D. Albrecht, and G. J. Pepe Inhibition of Fetal Adrenal Adrenocorticotropin Receptor Messenger Ribonucleic Acid Expression by Betamethasone Administration to the Baboon Fetus in Late Gestation Endocrinology, July 1, 1997; 138(7): 2705 - 2712. [Abstract] [Full Text] [PDF]

				S. Mesiano and R. B. Jaffe Developmental and Functional Biology of the Primate Fetal Adrenal Cortex Endocr. Rev., June 1, 1997; 18(3): 378 - 403. [Abstract] [Full Text]