Effects of eight weeks aerobic training on levels of amyloid β42, neprilysin and γ-secretase in the hippocampus of male rat alzheimer’s model by homocysteine injection

Abstract

© 2016, Semnan University of Medical Sciences. All rights reserved. Introduction: The aim of present study was to investigate the effects of eight weeks aerobic training on amyloid β42 (Aβ 1-42 ), neprilysin and γ-secretase levels in the hippocampus of male rat Alzheimer’s model by homocysteine injection. Materials and Methods: For this purpose, 50 male Wistar rats (12 weeks old) were divided into five groups, including: Alzheimer’s control, Alzheimer’s training, healthy control, healthy training and sham. To induce Alzheimer’s, homocysteine, with a concentration of 0.6M, was infused into the rat cerebroventriculum. To assess the memory impairment induced by homocysteine, the shuttle box test was used. Training groups, exercised using treadmill with 27m/min at 0◦ slope (75-80% VO2max, 60min/day, 5 days/week). Amyloid β42, neprilysin and γ-secretase levels were measured using rat ELISA kit. Results: The results showed that Aβ1-42 levels in the hippocampus of Alzheimer’s control group was significantly higher than healthy control and healthy training group (P=0.001). The level of γ-secretase in Alzheimer’s control group was significantly higher than healthy control, healthy training and sham groups (P=0.001). Likewise, levels of this factor in Alzheimer’s training group were significantly lower than Alzheimer’s control group (P=0.001). No significant differences were found between neprilysin levels in different groups (P=0.07). Mean level of Aβ1-42 showed a significant positive correlation with γ-secretase level (r = 0.54; P = 0.001). Conclusion: Based on these results, it s likely that continuous physical training can markedly reduce Aβ level in the hippocampus through reducing the level of γ-secretase and would be warrant to be considered as a complementary therapy in Alzheimer’s disease.