Endocrine Abstracts

Objectives: Alzheimer’s disease (AD) is the most common form of dementia in the elderly. AD is characterized by the presence of amyloid plaques which are formed from deposits of β-amyloid protein (Ab). These changes increase during menopausal condition in females when the level of oestradiol (E₂) is decreased. The aim of the present study was to determine the effect of neuropeptide, neurokinin B (NKB) and amyloid beta fragment Aβ (25–35) on E₂ treated aging female rat brain of 3 months (young), 12 months (adult), and 24 months (old) age groups.

Methods: The aged rats (12 and 24 months old) (n=8 for each group) were given s.c. injection of E₂ (0.1 μg/g body weight) daily for 1 month. After 30 days of hormone treatment, experimental animals of all the groups were sacrificed and brains were isolated for further study.

Results: The results obtained in the present work revealed that increased activities of antioxidant enzymes, membrane bound ATPases and decrease in level of calcium levels, monoamine oxidase activity and lipid peroxidation in presence of NKB and combined NKB and Aβ in vivo E₂ treated ageing rat brain. NKB treatment reversed the beneficial in preventing some of the age related changes in the brain. An in vitro incubation of E₂ treated synaptosomes with Aβ showed toxic effects on all the parameters, while NKB showed stimulating effects and the combined NKB and Aβ showed a partial effects as compared to Aβ (25–35) and NKB alone.

Conclusions: Present study elucidates an antioxidant, neuromodulatory and neuroprotective role of tachykinin peptide NKB against the β-amyloid induced toxicity in E₂ treated female rats. NKB treatment reversed the beneficial in preventing some of the age related changes in the brain.

Disclosure: CSIR grant 2005–6.