Antioxidative effects of allopurinol and sodium ascorbate increase posfatigue tension in avian skeletal muscle (LB809)

Muscle fatigue is conceived as a decrease in force development after periods of intense activity, and is considered a multifactorial process. Reactive oxygen species (ROS) could play an important role in the regulation of the signaling pathways involved in the proper functioning of muscles, particularly during fatigue. It has previously been reported that the use of antioxidants can reduce the development of fatigue and reverse the decline of force induced by ROS. Moreover, it has been reported that low concentrations of antioxidants are beneficial to the cells, while high concentrations may become detrimental. Although several studies indicate that mitochondria are the predominant site for ROS generation during activity, there has been considerable speculation concerning the role of xanthine oxidase in generation of ROS by skeletal muscle. The aim of this study was to determine the effect of Allopurinol (inhibitor of xanthine oxidase) and sodium ascorbate (ageneral antioxidant) during the muscle fatigue.Anterior Latissimus Dorsi (ALD) muscle of chicken was dissected and mounted on an experimental recording chamber by placing the proximal end to the bottom of the chamber and the distal end to the hook of a mechanic‐electric transducer (Grass FT03), which through an amplifier and a 320 CyberAmp analog‐digital interface (Digidata 1322A) allowed to acquire the muscle tension generated in a computer (Pentium 4) and a “software” of data acquisition (AXOTAPE, pCLAMP 9.2). We performed a fatigue protocol by twitches (pulses of 100 V, 300 ms duration, 0.5 Hz). The bundle was stimulated until the force decreased by 60 %, then was applied the study drug for 6 min to observe its effect. We used concentrations of Allopurinol (1uM, 10uM and 100 µM) and sodium ascorbate (10, 30 and 100 uM).In dose response curves the mayor effect for Allopurinol was 100 uM and 10 uM by sodium ascorbate. In combination of Allopurinol and sodium ascorbate the tension post‐fatigue increased to 27.24% ± 8.47% in peak tension, while in total tension was an increase by 53.38% ± 18.60% compared with fatigue. The post‐fatigue increase was similar in combination of both drugs that separately, this suggested us the necessity of certain amount of ROS for the normal behavior of the muscle, since both Allopurinol and sodium ascorbate might act as antioxidants.Grant Funding Source: Supported by CIC2014‐RMP