Central estrogen action sites involved in prepubertal restraint of pulsatile luteinizing hormone release in female rats

DOI Web Site Web Site PubMed 5 Citations 44 References Open Access
  • UENOYAMA Yoshihisa
    Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
  • TANAKA Akira
    Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
  • TAKASE Kenji
    Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
  • YAMADA Shunji
    Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
  • PHENG Vutha
    Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
  • INOUE Naoko
    Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
  • MAEDA Kei-ichiro
    Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo 113-8657, Japan
  • TSUKAMURA Hiroko
    Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan

Search this article

Abstract

The present study aimed to determine estrogen feedback action sites to mediate prepubertal restraint of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release in female rats. Wistar-Imamichi strain rats were ovariectomized (OVX) and received a local estradiol-17β (estradiol) or cholesterol microimplant in several brain areas, such as the medial preoptic area (mPOA), paraventricular nucleus, ventromedial nucleus and arcuate nucleus (ARC), at 20 or 35 days of age. Six days after receiving the estradiol microimplant, animals were bled to detect LH pulses at 26 or 41 days of age, representing the pre- or postpubertal period, respectively. Estradiol microimplants in the mPOA or ARC, but not in other brain regions, suppressed LH pulses in prepubertal OVX rats. Apparent LH pulses were found in the postpubertal period in all animals bearing estradiol or cholesterol implants. It is unlikely that pubertal changes in responsiveness to estrogen are due to a change in estrogen receptor (ER) expression, because the number of ERα-immunoreactive cells and mRNA levels of Esr1, Esr2 and Gpr30 in the mPOA and ARC were comparable between the pre- and postpubertal periods. In addition, kisspeptin or GnRH injection overrode estradiol-dependent prepubertal LH suppression, suggesting that estrogen inhibits the kisspeptin-GnRH cascade during the prepubertal period. Thus, estrogen-responsive neurons located in the mPOA and ARC may play key roles in estrogen-dependent prepubertal restraint of GnRH/LH secretion in female rats.

Journal

Citations (5)*help

See more

References(44)*help

See more

Related Projects

See more

Keywords

Details 詳細情報について

Report a problem

Back to top