COMPARATIVE STIMULATORY EFFECT OF GONADOTROPIN-RELEASING-HORMONE (GNRH) AND GNRH AGONIST UPON PULSATILE HUMAN CHORIONIC-GONADOTROPIN SECRETION IN SUPERFUSED PLACENTAL EXPLANTS - REVERSIBLE INHIBITION BY A GNRH ANTAGONIST

被引：29

作者：

BARNEA, ER

KAPLAN, M

NAOR, Z

机构：

[1] University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School at Camden, Cooper Hospital/University Medical Center, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Camden, NJ

[2] Feto-Placental Endocrinology Unit, Rappaport Institute Technion, Haifa, P.O. Box 9697, Efron Street

[3] Department of Biochemistry, Faculty of Life Science, University of Tel Aviv, Ramat Aviv

来源：

HUMAN REPRODUCTION | 1991年 / 6卷 / 08期

关键词：

CULTURE; GONADOTROPIN RELEASING HORMONE; HUMAN CHORIONIC GONADOTROPIN; PLACENTA; SUPERFUSION;

D O I：

10.1093/oxfordjournals.humrep.a137485

中图分类号：

R71 [妇产科学];

学科分类号：

100211 ;

摘要：

The roles of gonadotrophin releasing hormone (GnRH) and a GnRH agonist (GnRHa) (D-Ala6-Met-Leu7-Pro-N-ethylamide) in controlling pulsatile human chorionic gonadotrophin (HCG) secretion by superfused placental explants in the first trimester were examined. One minute pulses of both GnRH and GnRHa had a biphasic effect upon pulsatile HCG secretion. GnRHa was maximally effective at 10(-10) M concentration, at 10(-11) M the effect was mild while at 10(-8) M, no effect was noted. GnRH exerted a maximal stimulatory effect at 10(-8) M; at 10(-10) M no effect was seen, while at 10(-7) M the effect was mildly stimulatory. This was evaluated by carrying out both a between and within channel type of analysis. The effect of a GnRH antagonist GnRH(ant) upon GnRH and GnRHa-induced HCG secretion was examined. Explants were incubated overnight with 10(-8) M GnRH(ant), which was also continuously administered during superfusion. The addition of 1-min pulses of GnRH and GnRHa during the exposure to GnRH(ant) failed to stimulate pulsatile HCG secretion. This effect was reversible since the response to GnRH was restored within 10 min after stopping GnRH(ant) administration. In addition, by the third cycle, co-administration of GnRH(ant) for 2 min together with 10(-10) M GnRHa for 1 min completely blocked the GnRHa-induced effect. Continuous administration of 10(-8) M GnRH(ant) decreased spontaneous HCG pulse amplitude and the area under the curve but failed to modify pulse frequency. In conclusion, GnRH appears to exert a receptor-dependent stimulatory effect upon pulsatile HCG secretion in superfusion in the first trimester placenta. Also, GnRH(ant) may reduce spontaneous HCG pulsatility by blocking endogenous GnRH action.

引用

页码：1063 / 1069

页数：7

共 18 条

[1] Barnea E.R., Kaplan M., Gonadotropin releasing hormone- induced and progesterone-inhibited pulsatile secretion of human chorionic gonadotropin in the first trimester placenta in vitro, J. Clin. Endocrinol. Metab, 69, pp. 215-218, (1989)
[2] Barnea E.R., Feldman D., Kaplan M., Momsh D.W., The dual effect of epidermal growth factor upon human chorionic gonadotropin secretion by the first trimester placenta in vitro, J. Clin. Endocrinol. Metab, 71, pp. 923-928, (1990)
[3] Belisle S., Guevin J.F., Bellabarba D., Lehoux J.G., Luteinizing hormone-releasing hormone binds to enriched human placental membranes and stimulates in viiro the synthesis of bioactive human chorionic gonadotropin, J. Clin. Endocrinol. Metab, 59, pp. 119-124, (1984)
[4] Currie A.J., Fraser H.M., Scharpe R.M., Human placental receptors for luteinizing hormone releasing factor, Biochem. Biophvs. Res. Commun, 99, pp. 332-336, (1981)
[5] Kenisbcrg D., Litvnan B.A., Hodgen G.D., Medical hypophysectomy I: Dose-response using a GnRH antagonist, Fenil. Sterii, 42, pp. 112-116, (1984)
[6] Khodr G.S., Siler-Khodr T.M., The effect of luteinizing hormone-releasing factor on human chorionic gonadotropin secretion, Fertil. Sterii, 30, pp. 301-304, (1978)
[7] Kim S.I., Namkoong S.R., Lee J.W., Jung J.K., Kang B.C., Park J.S., Response of human chorionic gonadotropin to luteinizing hormone-releasing hormone stimulation in the culture media of normal human placenta, choriocarcinoma cell lines, and in the serum of patients with gestational trophoblastic disease, Placenta, 8, pp. 257-263, (1987)
[8] Loumaye E., Catt K.H., Agonist-induced regulation of pituitary receptors for gonadotropin releasing hormone, J. Biol. Chem, 258, pp. 12002-12004, (1983)
[9] Lowry O.H., Roscbrough N.A., Farr A.L., Randall R.J., Protein measurement with the folin phenol reagent, J. Biol. Chem, 193, pp. 230-265, (1951)
[10] Morrish D.W., Marusyk H., Siy O., Demonstration of specific secretory granules for human chorionic gonadotropin in placenta, J. Histochem. Cytochem, 35, pp. 93-101, (1987)

← 1 2 →