N-acetyl-L-cysteine inhibits exercise-induced lymphocyte apoptotic protein alterations

To investigate the effect of strenuous exercise and antioxidant administration on pro- and antiapoptotic protein expression in intestinal lymphocytes.

Female C57BL/6 mice (N = 52) were randomly assigned to receive N-acetyl-L-cysteine (NAC; 1 g.kg(-1)) or saline (SAL) 30 min before treadmill exercise (EX) for 90 min and 2 degrees slope (30 min at 22 m.min(-1), 30 min at 25 m.min(-1), and 30 min at 28 m.min(-1)) and sacrificed immediately (Imm) or 24 h (24 h) after exercise. Control mice were exposed to treadmill noise and vibration without running (nonexercised). Intestinal lymphocytes (IL) were isolated and pro- and antiapoptotic protein expression was evaluated by Western blot analysis.

IL protein levels of proapoptotic (caspase 3 and cytosolic cytochrome c) and antiapoptotic (Bcl-2) were significantly different among groups. Relative to nonexercised mice, protein levels of caspase 3 (P < 0.001) and cytosolic cytochrome c (P < 0.005) were significantly elevated, whereas Bcl-2 (P < 0.05) was significantly lower immediately after exercise in mice receiving saline (EX + SAL + Imm) but not in animals receiving NAC (EX + NAC + Imm) or both 24 h postgroups (EX + SAL + 24 h and EX + NAC + 24 h).

These results suggest that oxidative stress acting through a mitochondrial pathway may play a role in intestinal lymphocyte apoptosis after strenuous exercise.