L-Cysteine’s Effect on Modulated Rat Brain Enzymes with Forced Swimming

Abstract

Background:Forced exercise is associated with oxidative stress, and L-cysteine (L-cys) administration reduces free-radical production.Aim:To investigate whether L-cys (5 mg/kg) intraperitoneal administration can ameliorate modulated total antioxidant status (TAS), protein concentration, and the activities of acetylcholinesterase (AChE), (Na+,K+)-ATPase, and Mg2+-ATPase in rat brain after 2 and 3 hr of forced swimming.Methods:TAS, protein, and enzyme activities were measured spectrophotometrically before and after 2 and 3 hr of exercise without or with L-cys administration.Results:TAS concentration (55.6 ± 1.5 vs. 42.1 ± 1.0 vs. 37.4 ± 1.2 μmol/L, p < .001), protein concentration (5.68 ± 0.36 vs. 5.40 ± 0.18 vs. 4.01 ± 0.16 mg/ml, p < .01), and AChE activity (0.89 ± 0.05 vs. 0.61 ± 0.04 vs. 0.48 ± 0.03 ΔOD/min × mg protein, p < .001) were significantly reduced, whereas Na+,K+-ATPase (6.00 ± 0.36 vs. 10.44 ± 1.04 vs. 11.90 ± 1.21 µmol phosphorus inorganic/hr × mg protein, p < .001) and Mg2+-ATPase activity (7.20 ± 0.65 vs. 10.88 ± 1.08 vs. 11.55 ± 1.22 µmol phosphorus inorganic/hr × mg protein, p < .001) were statistically significantly increased after 2 and 3 hr of forced exercise. Post-L-cys administration, AChE activity was decreased (0.90 ± 0.04 vs. 0.47 ± 0.02 ΔOD/min × mg protein, p < .001) and remained unaltered (0.64 ± 0.04 vs. 0.67 ± 0.04 ΔOD/min × mg protein, p > .05) 2 and 3 hr postexercise (0.47 ± 0.02 vs. 0.54 ± 0.02 ΔOD/min × mg protein, p > .05). Na+,K+-ATPase was decreased and remained unchanged (1.85 ± 0.17 vs. 1.77 ± 0.19 µmol phosphorus inorganic/hr × mg protein, p > .05) 2 and 3 hr postswimming (1.91 ± 0.19 vs. 2.06 ±0.17 µmol phosphorus inorganic/hr × mg protein, p > .05). Mg2+-ATPase activity was similar with L-cys supplementation pre- vs. postswimming.Conclusions:L-cys administration might ameliorate modulated rat brain enzyme activities induced by free-radical production during forced swimming.