Background: Forced exercise produces free radicals and L-Carnitine (L-C) administration reduces oxidative stress. Aim: To investigate whether short (2h) or prolonged (3h) 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 (ip) administration of L-C (300 mg/kg). Method: 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 post 2h or 3h of training. L-C administration resulted in a profound restoration of TAS and protein concentration whereas AChE and Na+,K+-ATPase were increased pre- exercise, followed by a AChE restoration and Na+,K+-ATPase reduction post exercise. Mg2+-ATPase remained unchanged. An in vitro study with L-C incubation of brain homogenates previously treated with L-C resulted in a 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, whereas Na+,K+-ATPase and Mg2+-ATPase were activated. L-C administration may restore TAS and protein concentration, whereas AChE and Na+,K+-ATPase activities were decreased, the latters reached pre-exercise values after L-C incubation.
- Oxidative stress