Effect of Eight Weeks Endurance Training and nNOS Inhibition on Skeletal Muscle Nicotinic Acetylcholine Receptors level in Old Rats

The structure and function of neuromuscular junction (NMJ) changes significantly during aging and results in decrease of physical performance and sarcopenia. The purpose of this study was to determine the effect of eight weeks of endurance training and neuronal nitric oxide synthase (nNOS(inhibition on skeletal muscle nicotinic acetylcholine receptors (nAchR) in old rats. Endogenous NO production was blocked by two administering NG-nitro-L- arginine methyl ester (L-NAME) dosages (25 and 100 mg-1.kg-1.day-1) solved in drinking water. Forty eight old male Wistar rats (20 months) were randomly divided into six groups: control, LNAME25, LNAME100, endurance training with LNAME25, endurance training with LNAME100 and training. LNAME treatment began 48 hrs before exercise protocol and continued until the last day. Endurance training groups were exercised on treadmill for 8 weeks, 5 times a week and 60 minutes a day at velocity up to 28 m/min. Forty eight hours after last session of exercise training, animals were anesthetized and soleus and Extensor digitorum longus (EDL) were removed. Western Blotting analysis revealed that training increased nAchR level (P0.05) and nNOS inhibition decreased it (P0.05) compared to the control group. Our data showed that training groups which received LNAME (25 and 100 mg-1/kg-1/day-1), nAchR level increased significantly (P0.05) compare to control group. Our data suggested that daily endurance training could increase nAchR level even in rats which received LNAME and NO signaling has a role in regulation of nAchR level. In general, daily training could be a suitable route to reduce sarcopenia in aged population.