The Effect of Intracerebroventricular Injection of Beta Amyloid Peptide (1-42) on Caspase-3 Activity, Lipid Peroxidation, Nitric Oxide and NOS Expression in Young Adult and Aged Rat Brain

Aim: Intracerebroventricular (icv) administration of beta amyloid peptide (Aβ) in rats can be used to model certain aspects of Alzheimer disease (AD).The purpose of this study was to examine the effects of intracerebroventricular Aβ (1-42) peptide injection on caspase-3 activity and expression of nNOS and iNOS, malondialdehyde (MDA), glutathione (GSH) and NOx in the hippocampus, temporal cortex and parietal cortex.

Material And Methods: Groups were defined as 1) young adult control, 2) Aβ (1-42) injected young adult, 3) aged control and 4) Aβ (1-42) injected aged group. Stereotaxic surgery was performed. Aβ (1-42) peptide (5μg/1μl, in each icv) was administered bilateral intracerebroventricularly as a single injection.

Results: Caspase-3 activity significantly increased in Aβ (1-42) injected aged rats when compared with young adult rats. Aβ (1-42) significantly increased lipid peroxidation in both young adult and aged rats. There was an increase in nNOS expression in the temporal cortex of Aβ (1-42) injected aged rats.

Conclusion: The most significant increase was seen in hippocampus in caspase-3 levels of the Aged- Aβ 1-42 group. nNOS expression in the hippocampus of aged rats was increased compared to young adult rats. However, nNOX expression in the hippocampus of Aβ (1-42) injected aged rats decreased significantly.