Stimulatory effect of gonadotropin-releasing hormone (GnRH) on in vitro prolactin secretion and presence of GnRH specific receptors in a subset of human prolactinomas

1995 ◽  
Vol 132 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Anne Marie Brandi ◽  
Gaëlle Barrande ◽  
Najiba Lahlou ◽  
Michèle Crumeyrolle ◽  
Myriam Berthet ◽  
...  
Keyword(s):  
Gnrh Agonist ◽  
Direct Action ◽  
Prolactin Secretion ◽  
Gonadotropin Releasing Hormone ◽  
Α Subunit ◽  
Releasing Hormone ◽  
Gnrh Receptors ◽  
Specific Receptors ◽  
Indirect Immunoperoxidase

Brandi AM, Barrande G, Lahlou N, Crumeyrolle M, Berthet M, Leblanc P, Peillon F, Li JY. Stimulatory effect of gonadotropin-releasing hormone (GnRH) on in vitro prolactin secretion and presence of GnRH specific receptors in a subset of human prolactinomas. Eur J Endocrinol 1995;132:163–70. ISSN 0804–4643 The purpose of this study was to determine whether gonadotropin-releasing hormone (GnRH) may exert a direct action on human prolactinomas. On a series of 17 adenomas, we studied the effect of GnRH on the in vitro prolactin (PRL) secretion of dispersed and perifused cells of 10 cases and the [125I]GnRH agonist binding on frozen sections of three out of the adenomas studied in perifusion and on the membrane preparations of seven other cases. Two 20-min pulses of GnRH (10−7 mol/l) stimulated the in vitro PRL secretion of three adenomas out of 10 (increase of 200, 444 and 205%, respectively, above basal levels). The GnRH receptors of three adenomas bound GnRH agonist (Des-Gly10-(d-Ala6)-GnRH ethylamide). The binding was specific, with a high affinity (Kd = 0.60, 0.48 and 0.40 nmol/l) similar to that of two human anterior pituitaries obtained post-mortem (Kd = 0.70 and 0.40 nmol/l). Indirect immunoperoxidase revealed that the majority of the cells (60–90%) in all the adenomas studied contained immunoreactive PRL. Four of them also contained cells immunoreactive to the α-subunit of the glycoprotein hormones. In none of the prolactinomas were cells immunoreactive to antiserum of anti-β-luteinizing hormone, anti-β-follicle-stimulating hormone or anti-β-thyrotropin. All the prolactinomas that were responsive to GnRH in perifusion experiments and/or bound specifically to [125I]GnRH agonist were also immunoreactive for α-subunit. These results show that GnRH, via GnRH specific receptors, exerts a stimulation on in vitro PRL secretion in a subset of prolactinomas characterized by the presence of α-subunit. Anne Marie Brandi, Unité INSERM 223, Faculté de Médecine Pitié-Salpêtrière, 105 Boulevard de l'Hôpital, 75013 Paris, France

Long-term effects of a gonadotrophin-releasing hormone agonist ([d-Ser(But)6]GnRH(1–9)nonapeptide-ethylamide) on gonadotrophin secretion from human pituitary gonadotroph cell adenomas in vitro

1988 ◽  
Vol 118 (3) ◽  
pp. 491-496 ◽  
Author(s):  
M. Daniels ◽  
P. Newland ◽  
J. Dunn ◽  
P. Kendall-Taylor ◽  
M. C. White
Keyword(s):  
Gnrh Agonist ◽  
In Vitro Release ◽  
Long Term Effects ◽  
Human Pituitary ◽  
Α Subunit ◽  
Releasing Hormone ◽  
Gonadotrophin Secretion ◽  
Gonadotrophin Releasing Hormone

ABSTRACT We have studied the effects of TRH and native gonadotrophin-releasing hormone (GnRH), and of a GnRH agonist (Buserelin; [d-Ser(But)6]GnRH(1–9) nonapeptide-ethylamide), on LH, FSH, α subunit and LH-β subunit secretion from three human gonadotrophin-secreting pituitary adenomas in dispersed cell culture. During a 24 h study, treatment with 276 nmol TRH/1 resulted in a significant (P < 0·05) stimulated release of FSH and α subunit from all three adenomas, and LH from the two adenomas secreting detectable concentrations of this glycoprotein; treatment with 85 nmol GnRH/l significantly (P < 0·05) stimulated the release of α subunit from all three, but FSH from only two and LH from only one adenoma. During a long-term 28-day study, basal FSH and α subunit concentrations were maintained, but secretion of LH, and LH-β (detectable from one tumour only), declined with time from two of the three adenomas. Addition of Buserelin to the cultures resulted in the continuous (P < 0·05) stimulation of α subunit secretion from all three adenomas, and of LH and FSH from two, whilst a transient stimulatory effect on LH and FSH secretion was seen from a third adenoma, with subsequent secretion rates declining towards control values. These data show that human gonadotrophin-secreting adenomas demonstrate variable stimulatory responses to hypothalamic TRH and GnRH, and that during chronic treatment with a GnRH agonist the anticipated desensitizing effect of the drug was not observed in two out of three adenomas studied. The mechanism for this is not clear, but such drugs are unlikely to be of therapeutic value in the management of gonadotrophin-secreting tumours. The data also suggest that GnRH and GnRH agonists have a differential effect on the in-vitro release of intact gonadotrophins and the common α subunit. J. Endocr. (1988) 118, 491–496

scholarly journals Comparison of letrozole with gonadotropin-releasing hormone agonist in frozen embryo transfer after recurrent implantation failure: A randomized control trial

2020 ◽  
Author(s):  
Nayere Khadem Ghaebi ◽  
Malihe Mahmoudiniya ◽  
Mona Najaf Najafi ◽  
Elnaz Zohdi ◽  
Matin Attaran
Keyword(s):  
Embryo Transfer ◽  
Gnrh Agonist ◽  
Pregnancy Outcomes ◽  
Endometrial Thickness ◽  
Controlled Trial ◽  
Gonadotropin Releasing Hormone ◽  
Frozen Embryo Transfer ◽  
Fertilization In Vitro ◽  
Releasing Hormone

Background: The use of frozen embryo transfer (FET) is increasing worldwide in the treatment of infertility by in vitro fertilization. Different methods of endometrial preparation for FET have been suggested. Objective: The aim of this study was to compare the pregnancy outcomes after treatment with letrozole and those after treatment with the combination of gonadotropin-releasing hormone (GnRH) agonist and estradiol in FET. Materials and Methods: This randomized controlled trial study was conducted on 142 infertile women with a history of previous FET failure. Subjects were randomly assigned to one of two groups (n = 71 each). The GnRH group received 500 µg of buserelin plus 4mg estradiol (which increased to 8 mg if endometrial thickness was less than 5 mm), and the letrozole group received 5 mg of letrozole plus 75 IU of recombinant human follicle-stimulating hormone). At least two high-quality embryos were transferred to each subject in both groups. The outcome measures were clinical pregnancy rate and fetal heart rate detection Results: Subjects in the study groups had similar demographic characteristics and baseline clinical condition. Mean endometrial thickness in the letrozole and GnRH agonist groups were 8.90 ± 0.88 mm and 8.99 ± 0.85 mm, respectively (p = 0.57). The number of positive results of the beta human chorionic gonadotropin test and detection of fetal heartbeat were not significantly different between the groups (p > 0.05). Conclusions: The administration of letrozole and GnRH may produce similar pregnancy outcomes in FET. Key words: Letrozole; Fertilization in vitro; Pregnancy outcome.

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