Failure of estradiol to ameliorate global ischemia-induced CA1 sector injury in middle-aged female gerbils

Brain Res. 2007 Jun 11:1153:214-20. doi: 10.1016/j.brainres.2007.03.082. Epub 2007 Apr 1.

Abstract

Global forebrain ischemia arising from brief occlusion of the carotid arteries in gerbils produces selective hippocampal CA1 neuronal loss. Pre-treatment with 17beta-estradiol ameliorates, in part, ischemia-induced damage in young animals. Because stroke and cardiac arrest are more likely to occur among elderly individuals, neuroprotective studies in older animals have compelling clinical relevance. We investigated whether estradiol would attenuate ischemia-induced hippocampal neuronal injury in middle-aged (12-14 months) male, intact female, ovariectomized (OVX) female and OVX females treated for 14 days with estradiol. Core temperature telemetry probes were also implanted at the time that estradiol was initiated. Ischemia was induced by bilateral occlusion of the common carotid arteries (5 min), during which time skull temperature was maintained under normothermic conditions. Estradiol blocked the modest spontaneous hyperthermia that normally follows ischemia. However, all four groups exhibited substantial neuronal cell loss in the CA1, assessed at 7 after ischemia. These findings indicate that estradiol pre-treatment under conditions that produce neuroprotection in young animals does not protect against ischemia-induced CA1 cell loss in middle-aged female gerbils.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Brain Ischemia / complications
  • Brain Ischemia / drug therapy*
  • Brain Ischemia / pathology*
  • Cell Count
  • Cells, Cultured
  • Estradiol / blood
  • Estradiol / therapeutic use*
  • Female
  • Gerbillinae
  • Hippocampus / drug effects*
  • Hippocampus / pathology
  • Neurons / drug effects
  • Ovariectomy

Substances

  • Estradiol