Hypothalamic luteinizing hormone-releasing hormone (LHRH) and LH secretion in aging female rats

S. Takahashi, K. Nomura, S. Kawashima

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Age-related changes in hypothalamic luteinizing hormone-releasing hormone (LHRH) and luteinizing hormone (LH) secretion were studied in young (6 months), middle-aged (12 months) and old (18 months) female rats. The LHRH levels in the mid-hypothalamic area were higher in intact middle-aged and old females than in young ones. Additionally, there was no age difference in the hypothalamic LHRH levels in male rats. In order to clarify the significance of this age-related increase in female rats, we examined the effects of progesterone treatment in estrogen-primed ovariectomized young and old rats on the LHRH levels in the median eminence (ME) and on plasma LH levels. We found phasic changes in ME-LHRH and plasma LH levels in estrogen-primed rats following progesterone treatment in rats of both ages, but the progesterone-induced change in ME-LHRH levels tended to be delayed in old rats compared with young females. This delay may correspond to the delayed onset, slow and low magnitude of plasma LH increase in old females. the ME-LHRH levels were generally higher in old rats than in young rats. Nevertheless, we found that the increase in plasma LH in response to progesterone treatment in estrogen-primed ovariectomized females was smaller in old rats than young rats. These results suggest that the LHRH secretory mechanism changes with age in female rats. Such alterations may result in the accumulation of LHRH in the mid-hypothalamic area and an increase in ME-LHRH.

Original languageEnglish
Pages (from-to)213-221
Number of pages9
JournalEndocrinologia Japonica
Volume37
Issue number2
DOIs
Publication statusPublished - Jan 1 1990
Externally publishedYes

Fingerprint

Hypothalamic Hormones
Hormones
Luteinizing Hormone
Gonadotropin-Releasing Hormone
Rats
Aging of materials
Median Eminence
Progesterone
Plasmas
Estrogens

ASJC Scopus subject areas

  • Endocrinology
  • Engineering(all)

Cite this

Hypothalamic luteinizing hormone-releasing hormone (LHRH) and LH secretion in aging female rats. / Takahashi, S.; Nomura, K.; Kawashima, S.

In: Endocrinologia Japonica, Vol. 37, No. 2, 01.01.1990, p. 213-221.

Research output: Contribution to journalArticle

@article{2c83071f61714bb6b987be81ca5e5fa3,
title = "Hypothalamic luteinizing hormone-releasing hormone (LHRH) and LH secretion in aging female rats",
abstract = "Age-related changes in hypothalamic luteinizing hormone-releasing hormone (LHRH) and luteinizing hormone (LH) secretion were studied in young (6 months), middle-aged (12 months) and old (18 months) female rats. The LHRH levels in the mid-hypothalamic area were higher in intact middle-aged and old females than in young ones. Additionally, there was no age difference in the hypothalamic LHRH levels in male rats. In order to clarify the significance of this age-related increase in female rats, we examined the effects of progesterone treatment in estrogen-primed ovariectomized young and old rats on the LHRH levels in the median eminence (ME) and on plasma LH levels. We found phasic changes in ME-LHRH and plasma LH levels in estrogen-primed rats following progesterone treatment in rats of both ages, but the progesterone-induced change in ME-LHRH levels tended to be delayed in old rats compared with young females. This delay may correspond to the delayed onset, slow and low magnitude of plasma LH increase in old females. the ME-LHRH levels were generally higher in old rats than in young rats. Nevertheless, we found that the increase in plasma LH in response to progesterone treatment in estrogen-primed ovariectomized females was smaller in old rats than young rats. These results suggest that the LHRH secretory mechanism changes with age in female rats. Such alterations may result in the accumulation of LHRH in the mid-hypothalamic area and an increase in ME-LHRH.",
author = "S. Takahashi and K. Nomura and S. Kawashima",
year = "1990",
month = "1",
day = "1",
doi = "10.1507/endocrj1954.37.213",
language = "English",
volume = "37",
pages = "213--221",
journal = "Endocrine Journal",
issn = "0918-8959",
publisher = "Japan Endocrine Society",
number = "2",

}

TY - JOUR

T1 - Hypothalamic luteinizing hormone-releasing hormone (LHRH) and LH secretion in aging female rats

AU - Takahashi, S.

AU - Nomura, K.

AU - Kawashima, S.

PY - 1990/1/1

Y1 - 1990/1/1

N2 - Age-related changes in hypothalamic luteinizing hormone-releasing hormone (LHRH) and luteinizing hormone (LH) secretion were studied in young (6 months), middle-aged (12 months) and old (18 months) female rats. The LHRH levels in the mid-hypothalamic area were higher in intact middle-aged and old females than in young ones. Additionally, there was no age difference in the hypothalamic LHRH levels in male rats. In order to clarify the significance of this age-related increase in female rats, we examined the effects of progesterone treatment in estrogen-primed ovariectomized young and old rats on the LHRH levels in the median eminence (ME) and on plasma LH levels. We found phasic changes in ME-LHRH and plasma LH levels in estrogen-primed rats following progesterone treatment in rats of both ages, but the progesterone-induced change in ME-LHRH levels tended to be delayed in old rats compared with young females. This delay may correspond to the delayed onset, slow and low magnitude of plasma LH increase in old females. the ME-LHRH levels were generally higher in old rats than in young rats. Nevertheless, we found that the increase in plasma LH in response to progesterone treatment in estrogen-primed ovariectomized females was smaller in old rats than young rats. These results suggest that the LHRH secretory mechanism changes with age in female rats. Such alterations may result in the accumulation of LHRH in the mid-hypothalamic area and an increase in ME-LHRH.

AB - Age-related changes in hypothalamic luteinizing hormone-releasing hormone (LHRH) and luteinizing hormone (LH) secretion were studied in young (6 months), middle-aged (12 months) and old (18 months) female rats. The LHRH levels in the mid-hypothalamic area were higher in intact middle-aged and old females than in young ones. Additionally, there was no age difference in the hypothalamic LHRH levels in male rats. In order to clarify the significance of this age-related increase in female rats, we examined the effects of progesterone treatment in estrogen-primed ovariectomized young and old rats on the LHRH levels in the median eminence (ME) and on plasma LH levels. We found phasic changes in ME-LHRH and plasma LH levels in estrogen-primed rats following progesterone treatment in rats of both ages, but the progesterone-induced change in ME-LHRH levels tended to be delayed in old rats compared with young females. This delay may correspond to the delayed onset, slow and low magnitude of plasma LH increase in old females. the ME-LHRH levels were generally higher in old rats than in young rats. Nevertheless, we found that the increase in plasma LH in response to progesterone treatment in estrogen-primed ovariectomized females was smaller in old rats than young rats. These results suggest that the LHRH secretory mechanism changes with age in female rats. Such alterations may result in the accumulation of LHRH in the mid-hypothalamic area and an increase in ME-LHRH.

UR - http://www.scopus.com/inward/record.url?scp=0025179413&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025179413&partnerID=8YFLogxK

U2 - 10.1507/endocrj1954.37.213

DO - 10.1507/endocrj1954.37.213

M3 - Article

C2 - 2226340

AN - SCOPUS:0025179413

VL - 37

SP - 213

EP - 221

JO - Endocrine Journal

JF - Endocrine Journal

SN - 0918-8959

IS - 2

ER -