PURPOSE: This study aims to investigate the effects of voluntary exercise on liver levels of amyloid β (Aβ) and serum concentrations of LRP1, focusing on peripheral clearance in a rat Alzheimer's disease model. METHODS: Forty male Wistar rats (aged 4-6 weeks) were randomly divided into four groups: Healthy control, Alzheimer's disease (Alz), control + exercise (Con-Ex) and Alzheimer's disease + exercise (Alz-Ex). Alzheimer's disease was induced by an intraventricular STZ injection and the disease was confirmed with the shuttle box test. Rats randomized to the exercise intervention were given continuous access to a running wheel of 12 weeks. At the end of the study memory (Morris Water Maze), serum LRP1 level and liver Aβ40 were measured. Data were analyzed by one-way ANOVA and Tukey's post hoc test. RESULTS: The results of the study indicate that compared to Alz voluntary exercise significantly improved Morris Water Maze performance (Alz: 153.2 ± 19.95; Alz-Ex:106.8 ± 18.89; p<0.001) and decreased liver concentration of Aβ40 (Alz: 40.06 ± 6.17; Alz-Ex: 25.12 ± 2.92; p<0.001) levels similar to non-exercising control animals. Serum concentrations of LRP1 were not impacted by exercise. CONCLUSIONS: These results suggest that voluntary wheel running may positively reduce hepatic concentrations of Aβ40 in Alzheimer's disease independent of changes in circulating LRP1. Further research is needed to better understand the role of exercise in assisting in clearing Aβ40 in this model.
Zarnashan et al. (Wed,) studied this question.