L-cysteine's effect on modulated rat brain enzymes with forced swimming.
BACKGROUND
Forced exercise is associated with oxidative stress, and L-cysteine (L-cys) administration reduces free-radical production.


OBJECTIVE
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 micromol/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 DeltaOD/min x 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 micromol phosphorus inorganic/hr x mg protein, p < .001) and Mg2+-ATPase activity (7.20 +/- 0.65 vs. 10.88 +/- 1.08 vs. 11.55 +/- 1.22 mmol phosphorus inorganic/hr x 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 DeltaOD/min x mg protein, p < .001) and remained unaltered (0.64 +/- 0.04 vs. 0.67 +/- 0.04 DeltaOD/min x mg protein, p > .05) 2 and 3 hr postexercise (0.47 +/- 0.02 vs. 0.54 +/- 0.02 DeltaOD/min x mg protein, p > .05). Na+,K+-ATPase was decreased and remained unchanged (1.85 +/- 0.17 vs. 1.77 +/- 0.19 mumol phosphorus inorganic/hr x mg protein, p > .05) 2 and 3 hr postswimming (1.91 +/- 0.19 vs. 2.06 +/- 0.17 mumol phosphorus inorganic/hr x 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.
Tsakiris
Theodore
T
Department of Physiology, Medical School, Athens University, GR-15401 Athens, Greece.
Angelogianni
Panagoula
P
Tesseromatis
Christine
C
Tsakiris
Stylianos
S
Schulpis
Kleopatra H
KH
D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D003545:Cysteine / Q000494:pharmacology*; D005609:Free Radicals / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D010805:Physical Conditioning, Animal / Q000502:physiology; D011506:Proteins / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013550:Swimming / Q000502:physiology*
D000975:Antioxidants; D005609:Free Radicals; D011506:Proteins; D000110:Acetylcholinesterase; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D003545:Cysteine