Estradiol: A Protective and Trophic Factor in the Brain *

Abstract

In recent years our appreciation that estradiol is truly a pleiotropic hormone has grown dramatically. We will review the findings that suggest that estrogens1

¹

Estrogens are synthesized by the ovary and several other tissues. They contain 18 carbon atoms and an aromatized A ring. Estradiol is the predominant and most potent of the endogenously synthesized estrogens in adult premenopausal women. Preparations used in estrogen replacement therapy contain a variety of estrogenic compounds. Studies performed using laboratory animals have used a variety of estrogens to replace the endogenous steroid, including estradiol.

may exert important non-reproductive actions on the brain. These studies provide important insights into the clinical effects of estrogen replacement therapy on age- and disease-related processes in the brain. We will also discuss the multiple cellular and molecular mechanisms that may underlie estradiol's neurotrophic and neuroprotective effects.