Effect of gonadotropin secretion rate on the radiosensitivity of the rat luteinizing hormone-releasing hormone neuron and gonadotroph

J. Winterer, K. M. Barnes, A. S. Lichter, A. M. Deluca, Donald (Lynn) Loriaux, G. B. Cutler

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

To test the hypothesis that the functional state of hypothalamic LHRH neurons and pituitary gonadotrophs might alter their radiosensitivity, we determined the experimental conditions under which the gonadotropin response to castration could be impaired by a single dose of cranial irradiation. Single doses of cranial irradiation greater than 2000 rads were lethal to unshielded rats. Shielding of the oropharynx and esophagus allowed the animals to survive doses up to 5000 rads. Doses between 2000 and 5000 rads had no effect on basal gonadotropin levels for as long as 3 months after irradiation. Irradiation caused a dose- and time-dependent impairment, however, in the gonadotropin response to castration. Impairment of the gonadotropin levels of castrate animals occurred in animals that were irradiated either before or after castration. However, rats irradiated in the castrate state showed a decreased susceptibility to irradiation damage. Additionally, stimulation of the pituitary by LHRH agonist (LHRHa) 3 h before irradiation significantly reduced the impairment of gonadotropin secretion 12-20 weeks after irradiation (P <0.05). Thus, increased functional activity of the rat hypothalamus or pituitary at the time of irradiation, induced by either castration or acute LHRHa administration, was associated with some protection against the gonadotropin-lowering effect of irradiation. Based upon these data, we hypothesize that stimulation of gonadotropin secretion at the time of therapeutic cranial irradiation in humans might protect against subsequent impairment of gonadotropin secretion.

Original languageEnglish (US)
Pages (from-to)884-890
Number of pages7
JournalEndocrinology
Volume122
Issue number3
StatePublished - 1988
Externally publishedYes

Fingerprint

Gonadotrophs
Radiation Tolerance
Gonadotropins
Gonadotropin-Releasing Hormone
Neurons
Castration
Cranial Irradiation
Oropharynx
Esophagus
Hypothalamus

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism

Cite this

Effect of gonadotropin secretion rate on the radiosensitivity of the rat luteinizing hormone-releasing hormone neuron and gonadotroph. / Winterer, J.; Barnes, K. M.; Lichter, A. S.; Deluca, A. M.; Loriaux, Donald (Lynn); Cutler, G. B.

In: Endocrinology, Vol. 122, No. 3, 1988, p. 884-890.

Research output: Contribution to journalArticle

Winterer, J. ; Barnes, K. M. ; Lichter, A. S. ; Deluca, A. M. ; Loriaux, Donald (Lynn) ; Cutler, G. B. / Effect of gonadotropin secretion rate on the radiosensitivity of the rat luteinizing hormone-releasing hormone neuron and gonadotroph. In: Endocrinology. 1988 ; Vol. 122, No. 3. pp. 884-890.
@article{aafc898bbb4e475298c1ec48fa0731cd,
title = "Effect of gonadotropin secretion rate on the radiosensitivity of the rat luteinizing hormone-releasing hormone neuron and gonadotroph",
abstract = "To test the hypothesis that the functional state of hypothalamic LHRH neurons and pituitary gonadotrophs might alter their radiosensitivity, we determined the experimental conditions under which the gonadotropin response to castration could be impaired by a single dose of cranial irradiation. Single doses of cranial irradiation greater than 2000 rads were lethal to unshielded rats. Shielding of the oropharynx and esophagus allowed the animals to survive doses up to 5000 rads. Doses between 2000 and 5000 rads had no effect on basal gonadotropin levels for as long as 3 months after irradiation. Irradiation caused a dose- and time-dependent impairment, however, in the gonadotropin response to castration. Impairment of the gonadotropin levels of castrate animals occurred in animals that were irradiated either before or after castration. However, rats irradiated in the castrate state showed a decreased susceptibility to irradiation damage. Additionally, stimulation of the pituitary by LHRH agonist (LHRHa) 3 h before irradiation significantly reduced the impairment of gonadotropin secretion 12-20 weeks after irradiation (P <0.05). Thus, increased functional activity of the rat hypothalamus or pituitary at the time of irradiation, induced by either castration or acute LHRHa administration, was associated with some protection against the gonadotropin-lowering effect of irradiation. Based upon these data, we hypothesize that stimulation of gonadotropin secretion at the time of therapeutic cranial irradiation in humans might protect against subsequent impairment of gonadotropin secretion.",
author = "J. Winterer and Barnes, {K. M.} and Lichter, {A. S.} and Deluca, {A. M.} and Loriaux, {Donald (Lynn)} and Cutler, {G. B.}",
year = "1988",
language = "English (US)",
volume = "122",
pages = "884--890",
journal = "Endocrinology",
issn = "0013-7227",
publisher = "The Endocrine Society",
number = "3",

}

TY - JOUR

T1 - Effect of gonadotropin secretion rate on the radiosensitivity of the rat luteinizing hormone-releasing hormone neuron and gonadotroph

AU - Winterer, J.

AU - Barnes, K. M.

AU - Lichter, A. S.

AU - Deluca, A. M.

AU - Loriaux, Donald (Lynn)

AU - Cutler, G. B.

PY - 1988

Y1 - 1988

N2 - To test the hypothesis that the functional state of hypothalamic LHRH neurons and pituitary gonadotrophs might alter their radiosensitivity, we determined the experimental conditions under which the gonadotropin response to castration could be impaired by a single dose of cranial irradiation. Single doses of cranial irradiation greater than 2000 rads were lethal to unshielded rats. Shielding of the oropharynx and esophagus allowed the animals to survive doses up to 5000 rads. Doses between 2000 and 5000 rads had no effect on basal gonadotropin levels for as long as 3 months after irradiation. Irradiation caused a dose- and time-dependent impairment, however, in the gonadotropin response to castration. Impairment of the gonadotropin levels of castrate animals occurred in animals that were irradiated either before or after castration. However, rats irradiated in the castrate state showed a decreased susceptibility to irradiation damage. Additionally, stimulation of the pituitary by LHRH agonist (LHRHa) 3 h before irradiation significantly reduced the impairment of gonadotropin secretion 12-20 weeks after irradiation (P <0.05). Thus, increased functional activity of the rat hypothalamus or pituitary at the time of irradiation, induced by either castration or acute LHRHa administration, was associated with some protection against the gonadotropin-lowering effect of irradiation. Based upon these data, we hypothesize that stimulation of gonadotropin secretion at the time of therapeutic cranial irradiation in humans might protect against subsequent impairment of gonadotropin secretion.

AB - To test the hypothesis that the functional state of hypothalamic LHRH neurons and pituitary gonadotrophs might alter their radiosensitivity, we determined the experimental conditions under which the gonadotropin response to castration could be impaired by a single dose of cranial irradiation. Single doses of cranial irradiation greater than 2000 rads were lethal to unshielded rats. Shielding of the oropharynx and esophagus allowed the animals to survive doses up to 5000 rads. Doses between 2000 and 5000 rads had no effect on basal gonadotropin levels for as long as 3 months after irradiation. Irradiation caused a dose- and time-dependent impairment, however, in the gonadotropin response to castration. Impairment of the gonadotropin levels of castrate animals occurred in animals that were irradiated either before or after castration. However, rats irradiated in the castrate state showed a decreased susceptibility to irradiation damage. Additionally, stimulation of the pituitary by LHRH agonist (LHRHa) 3 h before irradiation significantly reduced the impairment of gonadotropin secretion 12-20 weeks after irradiation (P <0.05). Thus, increased functional activity of the rat hypothalamus or pituitary at the time of irradiation, induced by either castration or acute LHRHa administration, was associated with some protection against the gonadotropin-lowering effect of irradiation. Based upon these data, we hypothesize that stimulation of gonadotropin secretion at the time of therapeutic cranial irradiation in humans might protect against subsequent impairment of gonadotropin secretion.

UR - http://www.scopus.com/inward/record.url?scp=0023880387&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023880387&partnerID=8YFLogxK

M3 - Article

C2 - 3125043

AN - SCOPUS:0023880387

VL - 122

SP - 884

EP - 890

JO - Endocrinology

JF - Endocrinology

SN - 0013-7227

IS - 3

ER -