Caloric restriction reduces cell loss and maintains estrogen receptor-alpha immunoreactivity in the pre-optic hypothalamus of female B6D2F1 mice

Farzin Yaghmaie, Omar Saeed, Steven A. Garan, Warren Freitag, Paola S. Timiras, Hal Sternberg

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

Life-long calorie restriction (CR) remains the most robust and reliable means of extending life span in mammals. Among the several theories to explain CR actions, one variant of the neuroendocrine theories of aging postulates that changing hypothalamic sensitivity to endocrine feedback is the clock that times phenotypic change over the life span. If the feedback sensitivity hypothesis is correct, CR animals should display a significantly different pattern of hormone-sensitive cell density and distribution in the hypothalamus. Of the many endocrine signal receptors that may be involved in maintaining hypothalamic feedback sensitivity, our study has selected to begin mapping those for estrogen (E). Altered hypothalamic sensitivity to E is known to schedule reproductive maturation and influence reproductive senescence. Taking estrogen receptor-alpha (ERα) immunoreactivity as an index of sensitivity to E, we counted ERα immunoreactive and non-immunoreactive cells in the pre-optic hypothalamus of young (6 weeks), ad-libitum (Old-AL) fed old (22 months), and calorie restricted (Old-CR) old (22 months) female B6D2F1 mice. An automated imaging microscopy system (AIMS) was used to generate cell counts for each sampled section of pre-optic hypothalamus. Results show a 38% reduction in ERα immunoreactive cells and an 18% reduction in total cell numbers in AL-old mice in comparison to young mice. However, CR mice only show a 19% reduction in ERα immunoreactive cells and a 13% reduction in total cell numbers in comparison to young mice. This indicates CR prevents age-related cell loss and maintains estrogen sensitivity in the pre-optic hypothalamus of old female B6D2F1 mice.

Original languageEnglish (US)
Pages (from-to)197-203
Number of pages7
JournalNeuroendocrinology Letters
Volume26
Issue number3
StatePublished - Jun 1 2005
Externally publishedYes

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Keywords

  • Aging
  • Caloric restriction
  • Estrogen receptor-alpha
  • Hypothalamus

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Neurology
  • Endocrine and Autonomic Systems
  • Clinical Neurology
  • Psychiatry and Mental health

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