Activation of growth hormone short loop negative feedback delays puberty in the female rat

J. P. Advis, S. Smith-White, Sergio Ojeda

Research output: Contribution to journalArticle

99 Citations (Scopus)

Abstract

Implantation of GH in the median eminence of the hypothalamus of 23-day-old female rats tonically inhibited serum GH levels throughout prepubertal development (days 23-36) and depressed GH diurnal pulsatile release. Puberty was significantly delayed in GH-deficient animals, a delay associated with a blunted in vitro ovarian steroidal responsiveness to gonadotropins (particularly estradiol) and a marked decrease in prepubertal uterine weight, as evaluated 4, 7, and 13 days after GH implantation. The prepubertal body weight increase was also depressed. Neither ovarian weight nor serum levels of LH, FSH, PRL, or TSH were consistently altered by the GH implant. In addition, evaluation of pulsatile PRL release in 33-day-old rats revealed no difference between control and GH-deficient animals. Ovarian LH receptor content was lower in GH-implanted rats than in controls, suggesting that a decrease in LH receptors may be one of the mechanisms by which a chronic decrease in serum GH depressed the prepubertal ovarian estradiol and, to a lesser extent, the progesterone response to gonadotropins. A direct ovarian site of action for GH was indicated by the results of experiments in which GH was administered to immature hypophysectomized estrogen-treated rats. The in vitro ovarian progesterone response of the GH-treated animals to both hCG and human FSH was distinctly increased by prior in vivo GH treatment. This effect of GH was not reproduced either by the in vivo administration of LH at a dose calculated by RIA to be contaminating the GH preparation or by FSH at a dose that induced a marked increase in aromatase activity in the same ovaries. GH treatment of hypophysectomized rats failed to affect either aromatase activity or hCG-induced estradiol release, indicating that GH does not directly facilitate the production of estradiol by the ovary. The fact that intact rats with GH implants did not actually show a decrease in the ovarian estradiol response to hCG but, rather, failed to show an increased response at the same time as control animals strongly suggests that ovarian maturation was delayed in GH-deficient rats. It is suggested that, in addition to PRL, GH may also play a role in the process of prepubertal reproductive development by enhancing the steroidal response of the ovary to gonadotropins.

Original languageEnglish (US)
Pages (from-to)1343-1352
Number of pages10
JournalEndocrinology
Volume108
Issue number4
StatePublished - 1981
Externally publishedYes

Fingerprint

Puberty
Growth Hormone
Estradiol
Gonadotropins
LH Receptors
Ovary
Aromatase
Progesterone
Serum
Human Follicle Stimulating Hormone
Weights and Measures
Median Eminence
Hypothalamus
Estrogens
Body Weight

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism

Cite this

Activation of growth hormone short loop negative feedback delays puberty in the female rat. / Advis, J. P.; Smith-White, S.; Ojeda, Sergio.

In: Endocrinology, Vol. 108, No. 4, 1981, p. 1343-1352.

Research output: Contribution to journalArticle

Advis, J. P. ; Smith-White, S. ; Ojeda, Sergio. / Activation of growth hormone short loop negative feedback delays puberty in the female rat. In: Endocrinology. 1981 ; Vol. 108, No. 4. pp. 1343-1352.
@article{653073e527934fc4b7294fec988ecbb4,
title = "Activation of growth hormone short loop negative feedback delays puberty in the female rat",
abstract = "Implantation of GH in the median eminence of the hypothalamus of 23-day-old female rats tonically inhibited serum GH levels throughout prepubertal development (days 23-36) and depressed GH diurnal pulsatile release. Puberty was significantly delayed in GH-deficient animals, a delay associated with a blunted in vitro ovarian steroidal responsiveness to gonadotropins (particularly estradiol) and a marked decrease in prepubertal uterine weight, as evaluated 4, 7, and 13 days after GH implantation. The prepubertal body weight increase was also depressed. Neither ovarian weight nor serum levels of LH, FSH, PRL, or TSH were consistently altered by the GH implant. In addition, evaluation of pulsatile PRL release in 33-day-old rats revealed no difference between control and GH-deficient animals. Ovarian LH receptor content was lower in GH-implanted rats than in controls, suggesting that a decrease in LH receptors may be one of the mechanisms by which a chronic decrease in serum GH depressed the prepubertal ovarian estradiol and, to a lesser extent, the progesterone response to gonadotropins. A direct ovarian site of action for GH was indicated by the results of experiments in which GH was administered to immature hypophysectomized estrogen-treated rats. The in vitro ovarian progesterone response of the GH-treated animals to both hCG and human FSH was distinctly increased by prior in vivo GH treatment. This effect of GH was not reproduced either by the in vivo administration of LH at a dose calculated by RIA to be contaminating the GH preparation or by FSH at a dose that induced a marked increase in aromatase activity in the same ovaries. GH treatment of hypophysectomized rats failed to affect either aromatase activity or hCG-induced estradiol release, indicating that GH does not directly facilitate the production of estradiol by the ovary. The fact that intact rats with GH implants did not actually show a decrease in the ovarian estradiol response to hCG but, rather, failed to show an increased response at the same time as control animals strongly suggests that ovarian maturation was delayed in GH-deficient rats. It is suggested that, in addition to PRL, GH may also play a role in the process of prepubertal reproductive development by enhancing the steroidal response of the ovary to gonadotropins.",
author = "Advis, {J. P.} and S. Smith-White and Sergio Ojeda",
year = "1981",
language = "English (US)",
volume = "108",
pages = "1343--1352",
journal = "Endocrinology",
issn = "0013-7227",
publisher = "The Endocrine Society",
number = "4",

}

TY - JOUR

T1 - Activation of growth hormone short loop negative feedback delays puberty in the female rat

AU - Advis, J. P.

AU - Smith-White, S.

AU - Ojeda, Sergio

PY - 1981

Y1 - 1981

N2 - Implantation of GH in the median eminence of the hypothalamus of 23-day-old female rats tonically inhibited serum GH levels throughout prepubertal development (days 23-36) and depressed GH diurnal pulsatile release. Puberty was significantly delayed in GH-deficient animals, a delay associated with a blunted in vitro ovarian steroidal responsiveness to gonadotropins (particularly estradiol) and a marked decrease in prepubertal uterine weight, as evaluated 4, 7, and 13 days after GH implantation. The prepubertal body weight increase was also depressed. Neither ovarian weight nor serum levels of LH, FSH, PRL, or TSH were consistently altered by the GH implant. In addition, evaluation of pulsatile PRL release in 33-day-old rats revealed no difference between control and GH-deficient animals. Ovarian LH receptor content was lower in GH-implanted rats than in controls, suggesting that a decrease in LH receptors may be one of the mechanisms by which a chronic decrease in serum GH depressed the prepubertal ovarian estradiol and, to a lesser extent, the progesterone response to gonadotropins. A direct ovarian site of action for GH was indicated by the results of experiments in which GH was administered to immature hypophysectomized estrogen-treated rats. The in vitro ovarian progesterone response of the GH-treated animals to both hCG and human FSH was distinctly increased by prior in vivo GH treatment. This effect of GH was not reproduced either by the in vivo administration of LH at a dose calculated by RIA to be contaminating the GH preparation or by FSH at a dose that induced a marked increase in aromatase activity in the same ovaries. GH treatment of hypophysectomized rats failed to affect either aromatase activity or hCG-induced estradiol release, indicating that GH does not directly facilitate the production of estradiol by the ovary. The fact that intact rats with GH implants did not actually show a decrease in the ovarian estradiol response to hCG but, rather, failed to show an increased response at the same time as control animals strongly suggests that ovarian maturation was delayed in GH-deficient rats. It is suggested that, in addition to PRL, GH may also play a role in the process of prepubertal reproductive development by enhancing the steroidal response of the ovary to gonadotropins.

AB - Implantation of GH in the median eminence of the hypothalamus of 23-day-old female rats tonically inhibited serum GH levels throughout prepubertal development (days 23-36) and depressed GH diurnal pulsatile release. Puberty was significantly delayed in GH-deficient animals, a delay associated with a blunted in vitro ovarian steroidal responsiveness to gonadotropins (particularly estradiol) and a marked decrease in prepubertal uterine weight, as evaluated 4, 7, and 13 days after GH implantation. The prepubertal body weight increase was also depressed. Neither ovarian weight nor serum levels of LH, FSH, PRL, or TSH were consistently altered by the GH implant. In addition, evaluation of pulsatile PRL release in 33-day-old rats revealed no difference between control and GH-deficient animals. Ovarian LH receptor content was lower in GH-implanted rats than in controls, suggesting that a decrease in LH receptors may be one of the mechanisms by which a chronic decrease in serum GH depressed the prepubertal ovarian estradiol and, to a lesser extent, the progesterone response to gonadotropins. A direct ovarian site of action for GH was indicated by the results of experiments in which GH was administered to immature hypophysectomized estrogen-treated rats. The in vitro ovarian progesterone response of the GH-treated animals to both hCG and human FSH was distinctly increased by prior in vivo GH treatment. This effect of GH was not reproduced either by the in vivo administration of LH at a dose calculated by RIA to be contaminating the GH preparation or by FSH at a dose that induced a marked increase in aromatase activity in the same ovaries. GH treatment of hypophysectomized rats failed to affect either aromatase activity or hCG-induced estradiol release, indicating that GH does not directly facilitate the production of estradiol by the ovary. The fact that intact rats with GH implants did not actually show a decrease in the ovarian estradiol response to hCG but, rather, failed to show an increased response at the same time as control animals strongly suggests that ovarian maturation was delayed in GH-deficient rats. It is suggested that, in addition to PRL, GH may also play a role in the process of prepubertal reproductive development by enhancing the steroidal response of the ovary to gonadotropins.

UR - http://www.scopus.com/inward/record.url?scp=0019468590&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019468590&partnerID=8YFLogxK

M3 - Article

VL - 108

SP - 1343

EP - 1352

JO - Endocrinology

JF - Endocrinology

SN - 0013-7227

IS - 4

ER -