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

The aim of present study was to investigate the effects of eight weeks aerobic training on amyloid β42 (Aβ1-42), neprilysin and γ-secretase levels in the hippocampus of male rat Alzheimer's model by homocysteine injection.
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 Alzheimers, 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.
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).
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