抄録
Alzheimers disease (AD), the most common form of dementia in the elderly population, is characterized by an insidious onset with memory impairment and an inexorable progression of cognitive decline. Amyloid β peptide (Aβ) is a product of sequential cleaving of amyloid precursor protein (APP) by two proteolytic enzymes, β- and γ-secretases, which cleave the APP at the N and C terminus of Aβ, respectively. The age-related activities of these secretase may induce changes in turnover of Aβ and elevate the risk of AD. Epidemiologic studies show a relation between dietary fish oil and AD. DHA supplementation was shown to improve cognitive function in the elderly. Therefore aging and depletion of DHA are risk factors for AD. We hypothesized that imbalance of Aβ production may occur by aging and depletion of DHA. We examined what mechanisms involved in impairment the balance of Aβ generation by aging and depletion of DHA. We examined age-related changes of mRNA expressions in these proteins. One group of rats fed a fish oil deficient diet (F1 diet) through three generations. Other group of rats fed MF (normal rodent diet). The hippocampus and cerebral cortex were dissected from young (7 weeks old) and adult (50 weeks old) F1 or MF fed rats. Expressions levels of APP, β- site APP-cleaving enzyme (BACE), presenilin 1 (γ-secretase) and neprilysin mRNA in these tissues were measured by Real-Time PCR. [J Physiol Sci. 2007;57 Suppl:S176]
