Exercise natural killer cell activity

Prognosis is directly related to the severity of pulmonary injury. Animals that survive the first 24 to 48 h still have a guarded prognosis. These animals are more susceptible to infectious agents as they have suppressed natural killer cell activity. Infections may become evident 3 to 5 days after exposure. Animals may develop chronic exercise intolerance and abnormal pulmonary function (Borak and Diller, 2001). Working dogs and equines may no longer be able to fulfill their fimctions. 

Exercise poses a stress on the immune system however, moderate chronic exercise may enhance positive immune functions. Severe or intense long-term exercise may compromise the immune system by suppressing concentrations of lymphocytes, natural-killer cell activity, lymphocyte proliferation, and secretory IgA. During the period of immune impairment ( open window"), microbial agents may invade the host and cause infections. The changes in immune functions, lower exercise capacity, and nutritional factors in the elderly may lead to a greater and longer open window period, increased risk of infections which may contribute to morbidity and mortality. 

Strenuous exerdse can cause significant immunosuppression along with a reduction in plasma glutamine levels. Following intense exerdse of greater than 1 h, lymphocyte coimt, natural killer cell activity, and lymphokine-activated killer cell activity were observed to decline." " Additionally, the lymphocyte proliferative response to T-cell mitogens decreased during exercise. Concomitant decline in... 

---