The effect of taurine pre-supplementation on heart and plasma amyloidogenic protein levels (transthyretin, Aβ 1-42), plasma metal cation levels and brain LRP-1 levels in elderly rats with experimental Alzheimer's disease model

In this study, it was aimed to determine the plasma TTR, Aβ 1-42 and metal cation (Fe, Cu, Zn, Mn) levels in aged rats in which Alzheimer's disease model was created by intracerebroventricular Aβ 1-42 administration and to evaluate whether these parameters can be used as a blood-based biomarker for Alzheimer's disease. With the detection of brain LRP-1 level, it was desired to obtain information about the Aβ 1-42 transport mechanism of TTR. In addition, it was aimed to investigate the relationship between heart and brain amyloidosis by measuring cardiac TTR and Aβ 1-42 levels. In addition, it was desired to see the possible positive effect of taurine pre-supplementation on all measured parameters. In our study, 30 male Wistar albino rats, aged 28±2 months, were divided into 5 groups as control, sham, Aβ 1-42, taurine and taurine + Aβ 1-42, n=6. Rats in taurine and taurine + Aβ 1-42 groups were pre-supplemented with 1000 mg/kg/day taurine by mixing them with drinking water. Then, an Alzheimer's disease model was created by injecting intracerebroventricular Aβ 1-42 to Aβ 1-42 and taurine + Aβ 1-42 groups. After a 2-week waiting period, the animals were sacrificed under anesthesia. In our study, plasma metal cation levels were determined by ICP-MS method, plasma and cardiac TTR and Aβ 1-42 levels were determined by elisa kit using spectrophotometric method, and brain tissue LRP-1 levels were determined by western blot experiment. The Kruskal Wallis test and then the post-hoc Mann Whitney U test with Bonferroni correction were used for the analysis of the data and p<0.05 was considered significant. According to our findings, plasma copper, cardiac Aβ 1-42, cardiac TTR and brain LRP-1 levels were found to be decreased in the Alzheimer's disease model Aβ 1-42 group (p<0.05). There was no significant difference between the groups in terms of plasma iron, zinc, manganese levels, and plasma TTR and Aβ 1-42 levels. It was concluded that these evaluated parameters have the potential to be used as a biomarker for Alzheimer's disease, but more studies are needed to standardize them. The amino acid taurine, on the other hand, showed positive effects on Alzheimer's disease by protecting the cardiac TTR level, decreasing the cardiac Aβ 1-42 level, increasing the brain LRP-1 level and also bringing the plasma copper imbalance to a normal level. Keywords: Alzheimer's disease, taurine, transthyretin, LRP-1, metal cations