RESUMO
Endurance training improves the activity of G[4] type acetylcholine esterase [AchE] in muscle fibres. The purpose of this study was to investigate the effects of 8 weeks of endurance training [ET] on activity of A12 type of AchE in Flexor Hallucis Longus [FHL] and Soleus [SOL] muscles of rats. 16 male wistar rats [age: 10 weeks and weight: 172.17 +/- 10.080 gr], were randomly divided in 2 groups [control; N=8 and ET; N=8]. Training group carried out 8 weeks [5 session/week] of endurance training on animal treadmill with speed of 10 m/min for 30 min at the first week which was gradually increased to 30 m/min for 60 min [70-80% of VO[2]max] at the last week. Forty eight hours after last session of training, FHL and Sol muscles of animals were moved out under sterilized situation by cutting on posterio-lateral side of hind limb. For separating AchE subunits, homogenization and electrophoresis [0.06 non-denaturaing polyacrilamide] methods were used. AchE activity was measured by Elisa kit. The activity of this protein significantly [p=0.017] increased in SOL muscle of ET group by 119%, but did not changed in FHL. In both groups [ET and Con], FHL muscle had significantly [ET: p=0.028 and Con p=0.01] higher basic levels of AchE activity compared to SOL muscle. This significant increase in AchE of SOL might be indicative of responsiveness of AchE of this muscle following endurance training for improving acetylcholine [Ach] cycle in neuromuscular junction. Endurance training might increase the A[12] type AchE activity to improve the Ach cycle as part of the adaptation of neuromuscular junction to increased level of physical activity