Journal of Clinical Endocrinology & Metabolism, Vol 57, 812-818, Copyright © 1983 by Endocrine Society

ARTICLES

Characterization of the synthesis and release of human placental lactogen and human chorionic gonadotropin by an enriched population of dispersed placental cells

P Zeitler, E Markoff and S Handwerger

An enriched fraction of human placental cells that synthesize and release both placental lactogen (hPL) and hCG was obtained by isopycnic centrifugation of collagenase/hyaluronidase-dispersed cells through a density gradient of 40% Percoll. The enriched cells, which banded at a density of approximately 1.01 g/ml, comprised 10-15% of the total DNA. During the first 24 h after attachment, the cells released 50-250 ng hPL and 4-10 mIU hCG/10(6) cells. Thereafter, the rate of hPL release decreased, while the rate of hCG and [35S]trichloroacetic acid- precipitable protein release remained constant. The enriched cells responded to phospholipase A2, low extracellular calcium, and (Bu)2cAMP in a manner similar to that of placental explants. Phospholipase A2 (0.1 and 1 U/ml) stimulated hPL release by 270% and 568%, respectively, and low extracellular calcium (0-0.18 mM) stimulated hPL release by 48%. (Bu)2 cAMP (1 mM) stimulated hCG release by 42%, but had no effect on hPL. Estradiol (10(-5)-10(-12) M) and progesterone (10(-5)-10(-10) M) had no effect on the synthesis and release of either hPL or hCG over a 6-day period. In addition, insulin (8.3 X 10(-7) M) and changes in medium glucose content (0-5 mg/ml) had no effect on hPL release over a 72-h period. Since the enriched trophoblast cells respond to provocative stimuli in a manner similar to that of explants and placental fragments, this cell population is a useful model system for investigations of the cellular mechanisms of hPL and hCG release.

This article has been cited by other articles:

				S. S D'Souza, A. T Fazleabas, P. Banerjee, J. R. A Sherwin, A. M Sharkey, M. C Farach-Carson, and D. D Carson Decidual Heparanase Activity Is Increased During Pregnancy in the Baboon (Papio anubis) and in In Vitro Decidualization of Human Stromal Cells Biol Reprod, February 1, 2008; 78(2): 316 - 323. [Abstract] [Full Text] [PDF]

				B. Musicki, G. J. Pepe, and E. D. Albrecht Functional Differentiation of the Placental Syncytiotrophoblast: Effect of Estrogen on Chorionic Somatomammotropin Expression during Early Primate Pregnancy J. Clin. Endocrinol. Metab., September 1, 2003; 88(9): 4316 - 4323. [Abstract] [Full Text] [PDF]

				F Petraglia, P Sawchenko, A. Lim, J Rivier, and W Vale Localization, secretion, and action of inhibin in human placenta Science, July 10, 1987; 237(4811): 187 - 189. [Abstract] [PDF]