Effect of Estrogen on Brain Docosahexaenoic Acid Level and Spatial Learning Memory Performance

• Main Authors: JEN-JUI CHEN, 陳人睿
• Other Authors: Hui-Min Su
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/16509839339394353418

碩士 === 國立臺灣大學 === 生理學研究所 === 95 === Background: Postmenopausal women who take estrogen therapy have higher plasma DHA level and women have higher DHA level in plasma than men, indicating estrogen may play an important role for DHA accumulation in tissues. Aim: The study is to determine whether estrogen deprivation could decrease DHA deposition in brain regions and peripheral tissues. Material and method: DHA deficient rats were created by feeding DHA deficient diet for one generation. The DHA deficient rats (F2) and the chow diet feeding animal (F1) were ovariectomized (OVX) or sham operation either at age of 60 days old as adult group or at age of 8-12 months old as aging group. Animals were sacrificed 2-3 months after the surgery. Results: The DHA level in the brain regions and peripheral tissue of aging F2 was declined after ovariectomy. The loss percentage of DHA compared with the sham operation aging F2 was 36% in erythrocyte, 35% in hypothalamus, 33% in olfactory bulb, 31% in liver. The DHA level in erythrocyte and liver was decreased 25% and 22%, respectively, in the aging F1 after ovariectomy. However, DHA level in the brain regions was not changed. The DHA level in the brain regions and peripheral tissue was not decreased in adult F2 after ovariectomy. Brain estradiol concentration was not reduced after ovariectomy in the aging or the adult groups. However, estrogen receptor β expression in hippocampus was down regulated after ovariectomy in the aging F1 and aging F2 group. Conclusion: The DHA level in the brain regions and peripheral tissues was reduced, ERβ expression was down-regulated, but the brain estradiol concentration was not decreased in the aging DHA deficient rats with ovariectomy. It was suggested that circulation estrogen may play a role in brain DHA accumulation.