Effect of L-carnitine administration on the modulated rat brain protein concentration, acetylcholinesterase, Na+K+-ATPase and Mg2+-ATPase activities induced by forced swimming

Background: Forced exercise produces free radicals and L-carnitine (L-C) administration reduces oxidative stress. Aim: To investigate whether short ( 2 hours) or prolonged ( 3 hours) forced swimming could modulate total antioxidant status (TAS), protein concentration and activities of acetylcholinesterase (AChE), Na+K+-ATPase and Mg2+-ATPase in rat brain following intraperitonal administration of L-C ( 300 mg/kg). Methods: TAS, protein and enzyme activities were measured spectrophotometrically. Results: TAS, protein concentration and AChE activity were reduced, whereas Na+K+-ATPase and Mg2+-ATPase were significantly increased after either 2 or 3 hours of training. L-C administration resulted in a profound restoration of TAS and protein concentration whereas AChE and Na+K+-ATPase were increased before exercise, followed by AChE restoration and Na+K+-ATPase reduction after exercise. Mg2+-ATPase remained unchanged. An in vitro study using L-C incubation of brain homogenates previously treated with L-C resulted in complete restoration of the modulated enzymes, whereas the enzyme activities from untreated animals remained unaltered. Conclusions: Short or prolonged swimming in rats may result in a reduction of brain TAS, protein concentration and AChE activity, and an activation of Na+K+-ATPase and Mg2+-ATPase. L-C administration may prevent reduction in TAS and protein concentration, and a decrease in AChE and Na+K+-ATPase activity; the latter reached pre-exercise values after L-C incubation.