Inhibitory effect of a highly potent antagonist of LH releasing hormone (SB-75) on the pituitary gonadal axis in the intact and castrated rat

D. Ayalon, Y. Farhi, A. M. Comaru-Schally, Andrew V Schally, N. Eckstein, I. Vagman, R. Limor

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The biological potency of the new, highly potent antagonist [AC-D-Nal (2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10] LH-RH (SB-75) on the pituitary-gonadal system of female castrated and intact ovulating rats was tested. Administration of a single dose (50-100 μg/kg BW) of the antagonist SB-75 inhibited effectively the elevated gonadotrophin levels for 48 h. Pituitary LH and FSH content was not affected by SB-75 treatment. When administered in the early afternoon of the proestrus to intact cycling rats, SB-75 blocked the preovulatory LH surge as well as the primary and secondary FSH surges. However, the secondary FSH surge was not affected by SB-75 treatment when administered on the evening of proestrus suggesting its independence from the LH-RH mechanism. A group of ovariectomized rats was chronically treated with D-Trp6-LH-RH after having been pretreated by administration of a single dose of the antagonist. The initial stimulatory release of LH and FSH initiated by injection of the LH-RH agonist was significantly reduced by pretreatment with the LH-RH antagonist. We conclude that the LH-RH antagonist SB-75 may be used effectively in the field of reproductive dysfunction and endocrinological oncology and may become an invaluable physiological probe in studying the hormonal dynamics of the reproductive endocrine axis.

Original languageEnglish
Pages (from-to)153-159
Number of pages7
JournalNeuroendocrinology
Volume58
Issue number2
StatePublished - Jan 1 1993
Externally publishedYes

Fingerprint

Gonadotropin-Releasing Hormone
Proestrus
Gonadotropins
cetrorelix
Injections
Therapeutics

Keywords

  • Follicle-stimulating hormone
  • Luteinizing hormone
  • Luteinizing-hormone-releasing hormone antagonist
  • Ovariectomy

ASJC Scopus subject areas

  • Endocrinology
  • Neuroscience(all)

Cite this

Inhibitory effect of a highly potent antagonist of LH releasing hormone (SB-75) on the pituitary gonadal axis in the intact and castrated rat. / Ayalon, D.; Farhi, Y.; Comaru-Schally, A. M.; Schally, Andrew V; Eckstein, N.; Vagman, I.; Limor, R.

In: Neuroendocrinology, Vol. 58, No. 2, 01.01.1993, p. 153-159.

Research output: Contribution to journalArticle

Ayalon, D, Farhi, Y, Comaru-Schally, AM, Schally, AV, Eckstein, N, Vagman, I & Limor, R 1993, 'Inhibitory effect of a highly potent antagonist of LH releasing hormone (SB-75) on the pituitary gonadal axis in the intact and castrated rat', Neuroendocrinology, vol. 58, no. 2, pp. 153-159.
Ayalon, D. ; Farhi, Y. ; Comaru-Schally, A. M. ; Schally, Andrew V ; Eckstein, N. ; Vagman, I. ; Limor, R. / Inhibitory effect of a highly potent antagonist of LH releasing hormone (SB-75) on the pituitary gonadal axis in the intact and castrated rat. In: Neuroendocrinology. 1993 ; Vol. 58, No. 2. pp. 153-159.
@article{f5f932e9cd2643a3a73cf02b5760acc3,
title = "Inhibitory effect of a highly potent antagonist of LH releasing hormone (SB-75) on the pituitary gonadal axis in the intact and castrated rat",
abstract = "The biological potency of the new, highly potent antagonist [AC-D-Nal (2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10] LH-RH (SB-75) on the pituitary-gonadal system of female castrated and intact ovulating rats was tested. Administration of a single dose (50-100 μg/kg BW) of the antagonist SB-75 inhibited effectively the elevated gonadotrophin levels for 48 h. Pituitary LH and FSH content was not affected by SB-75 treatment. When administered in the early afternoon of the proestrus to intact cycling rats, SB-75 blocked the preovulatory LH surge as well as the primary and secondary FSH surges. However, the secondary FSH surge was not affected by SB-75 treatment when administered on the evening of proestrus suggesting its independence from the LH-RH mechanism. A group of ovariectomized rats was chronically treated with D-Trp6-LH-RH after having been pretreated by administration of a single dose of the antagonist. The initial stimulatory release of LH and FSH initiated by injection of the LH-RH agonist was significantly reduced by pretreatment with the LH-RH antagonist. We conclude that the LH-RH antagonist SB-75 may be used effectively in the field of reproductive dysfunction and endocrinological oncology and may become an invaluable physiological probe in studying the hormonal dynamics of the reproductive endocrine axis.",
keywords = "Follicle-stimulating hormone, Luteinizing hormone, Luteinizing-hormone-releasing hormone antagonist, Ovariectomy",
author = "D. Ayalon and Y. Farhi and Comaru-Schally, {A. M.} and Schally, {Andrew V} and N. Eckstein and I. Vagman and R. Limor",
year = "1993",
month = "1",
day = "1",
language = "English",
volume = "58",
pages = "153--159",
journal = "Neuroendocrinology",
issn = "0028-3835",
publisher = "S. Karger AG",
number = "2",

}

TY - JOUR

T1 - Inhibitory effect of a highly potent antagonist of LH releasing hormone (SB-75) on the pituitary gonadal axis in the intact and castrated rat

AU - Ayalon, D.

AU - Farhi, Y.

AU - Comaru-Schally, A. M.

AU - Schally, Andrew V

AU - Eckstein, N.

AU - Vagman, I.

AU - Limor, R.

PY - 1993/1/1

Y1 - 1993/1/1

N2 - The biological potency of the new, highly potent antagonist [AC-D-Nal (2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10] LH-RH (SB-75) on the pituitary-gonadal system of female castrated and intact ovulating rats was tested. Administration of a single dose (50-100 μg/kg BW) of the antagonist SB-75 inhibited effectively the elevated gonadotrophin levels for 48 h. Pituitary LH and FSH content was not affected by SB-75 treatment. When administered in the early afternoon of the proestrus to intact cycling rats, SB-75 blocked the preovulatory LH surge as well as the primary and secondary FSH surges. However, the secondary FSH surge was not affected by SB-75 treatment when administered on the evening of proestrus suggesting its independence from the LH-RH mechanism. A group of ovariectomized rats was chronically treated with D-Trp6-LH-RH after having been pretreated by administration of a single dose of the antagonist. The initial stimulatory release of LH and FSH initiated by injection of the LH-RH agonist was significantly reduced by pretreatment with the LH-RH antagonist. We conclude that the LH-RH antagonist SB-75 may be used effectively in the field of reproductive dysfunction and endocrinological oncology and may become an invaluable physiological probe in studying the hormonal dynamics of the reproductive endocrine axis.

AB - The biological potency of the new, highly potent antagonist [AC-D-Nal (2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10] LH-RH (SB-75) on the pituitary-gonadal system of female castrated and intact ovulating rats was tested. Administration of a single dose (50-100 μg/kg BW) of the antagonist SB-75 inhibited effectively the elevated gonadotrophin levels for 48 h. Pituitary LH and FSH content was not affected by SB-75 treatment. When administered in the early afternoon of the proestrus to intact cycling rats, SB-75 blocked the preovulatory LH surge as well as the primary and secondary FSH surges. However, the secondary FSH surge was not affected by SB-75 treatment when administered on the evening of proestrus suggesting its independence from the LH-RH mechanism. A group of ovariectomized rats was chronically treated with D-Trp6-LH-RH after having been pretreated by administration of a single dose of the antagonist. The initial stimulatory release of LH and FSH initiated by injection of the LH-RH agonist was significantly reduced by pretreatment with the LH-RH antagonist. We conclude that the LH-RH antagonist SB-75 may be used effectively in the field of reproductive dysfunction and endocrinological oncology and may become an invaluable physiological probe in studying the hormonal dynamics of the reproductive endocrine axis.

KW - Follicle-stimulating hormone

KW - Luteinizing hormone

KW - Luteinizing-hormone-releasing hormone antagonist

KW - Ovariectomy

UR - http://www.scopus.com/inward/record.url?scp=0027442280&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027442280&partnerID=8YFLogxK

M3 - Article

C2 - 8264861

AN - SCOPUS:0027442280

VL - 58

SP - 153

EP - 159

JO - Neuroendocrinology

JF - Neuroendocrinology

SN - 0028-3835

IS - 2

ER -