The effect of intracerebroventricular amyloid beta 1-42 application on cognitive functions in aged rats supplemented with taurine and the change of peroxisomal proteins in this process.

OBJECTIVE

The aim of our study is to investigate the change of peroxisomal proteins in the neurodegenerative and oxidative process caused by the neurotoxicity of Aβ 1-42 in aged rats supplemented with taurine and to show the possible positive effects of taurine in this process.

METHODS

30 Wistar albino rats were randomly divided into 5 groups as control, sham, Aβ 1-42, taurine, and Aβ 1-42+taurine. Taurine administration continued for 6 weeks (1000 mg/kg/day with drinking water). Stereotaxic surgery was applied to all groups (intracerebroventricular per lateral ventricle needle only or 5 μl, PBS, or Aβ 1-42). Spatial learning and memory performances of the animals were evaluated with Morris water maze and elevated plus maze. The levels of MDA and GSH were measured as oxidative stress parameters in the cerebral cortex and hippocampus. Expressions of CAT, PEX14, PMP70 of peroxisomal membrane proteins were indicated by Western blot analysis.

RESULTS

Our results showed that injection of Aβ 1-42 decreased the spatial learning and memory performance, cortex CAT and hippocampus PEX14, PMP70 and GSH levels, and increased cortex and hippocampus MDA levels (p < 0.05). Although the administration of taurine partially ameliorated the adverse effects of Aβ 1-42 injection, a significant difference was found only at the hippocampus GSH levels (p < 0.05). Also, taurine caused anxiety at this dose (p < 0.05).

DISCUSSION

In conclusion, decreased peroxisomal proteins and antioxidant capacity in neurodegenerative and oxidative processes induced by intracerebroventricular Aβ 1-42 injection showed that peroxisomes may play a role in this process and taurine supplementation may have positive effects especially in increasing antioxidant capacity.