The effect of high intensity exercise on the functional capacity of equinepulmonary alveolar macrophages and BAL-derived lymphocytes

The effect of strenuous exercise on the functional capacity of pulmonary al veolar macrophages (PAM) and bronchoalveolar lavage-derived lymphocytes was determined in eight horses prior to and after 7 weeks of training. Strenuo us exercise had no effect on the total cell count or the percentage of live cells in bronchoalveolar lavage (BAL) samples prior to or following traini ng. However, training was associated with a significant increase in the tot al cell count of pre-exercise BAL samples and a significant reduction in th e percentage of live cells in post-exercise samples. Strenuous exercise was associated with impaired phagocytosis by PAM after 7 weeks of training but had no effect on similar samples obtained from untrained horses. The oxida tive burst activity of PAM was significantly increased following strenuous exercise for both untrained and trained horses. BAL-derived lymphocyte oxid ative burst was similarly affected following training. These results sugges t that strenuous exercise and training may influence pulmonary immune cell function.