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Hormone receptors in the brain and relevance to reproductive aging
Author(s) -
Gore Andrea C,
Wu Di,
Yin Weiling,
Chakraborty Tandra R
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.231.2
Subject(s) - medicine , endocrinology , androgen receptor , testosterone (patch) , estrogen receptor , receptor , biology , androgen , sex steroid , hypothalamus , hormone , estrogen , sex hormone receptor , estrogen receptor alpha , steroid , prostate cancer , cancer , breast cancer
The control of reproductive physiology and behavior involves a complex hypothalamic circuitry that both drives, and responds to, gonadal steroid hormones. To determine effects of aging on expression of steroid hormone receptors, we quantified estrogen receptor alpha (ER) and androgen receptor (AR) immunoreactive cells in two key neuroendocrine brain regions: anteroventral periventricular nucleus (AVPV) and medial preoptic nucleus (MPN). Female and male Sprague‐Dawley rats were perfused at young (4 mo), middle‐aged (12 mo) and old (20–24 mo) ages. Females were ovariectomized and treated with estradiol (E2) or vehicle. Male rats were intact. In female rats, numbers of ER cells increased modestly with age in AVPV and MPN, with few effects of hormone treatment. In male rats, AR cell numbers and density increased robustly (3–6x), and ER increased slightly, in both regions during aging. These results are surprising because in females, E2 treatment down‐regulates ER mRNA levels, but we observe little effect of E2 on ER cell numbers, suggesting a disconnect between transcriptional and post‐transcriptional processes. In males, androgen levels decrease with age, but AR immunoreactivity increases dramatically, despite evidence that testosterone up‐regulates its receptors. These results suggest a dysregulation of nuclear receptors in the aging hypothalamus. Funding: AG16765 and AG028051.