Effects of swimming exercise on the pathogenesis of acute murine Toxoplasma gondii Me49 infection.

The effects of swimming exercise on the pathogenesis of acute murine toxoplasma infection were studied. Swimming (45 min/day) initiated on the day of inoculation with the avirulent Me49 strain of Toxoplasma gondii did not alter survival of infected mice. At a later stage of infection, daily swimming appeared to promote the recovery of appetite and weight gain. Immune activation was apparent in toxoplasma-infected mice, and swimming blunted splenic enlargement but not the respiratory burst activity of peritoneal exudate cells. Infection caused a significant elevation of serum tumor necrosis factor (TNF) levels which was attenuated by a daily swimming program. These data show that swimming exercise is not deleterious to mice acutely infected with T. gondii Me49 and that the more rapid recovery in exercised mice is associated with reduced serum TNF levels.