Activation of Leukocytes During Prolonged Physical Exercise

Abstract

In recent years, many forms of physical exercise have been considerably propagated in western societies. Therefore, many investigators have turned their interest towards the metabolic alterations, induced by enhanced physical training. Moorthy and Zimmermann reported an increase in the number of circulating leukocytes (1) during prolonged exercise, whereas Hedfors et al. (2) showed a phase of lymphocytosis following short-time exercise. Body core temperature was found to be increased after lengthy exercise (3). Furthermore, an increment of plasma levels of acute-phase proteins, such as C-reactive protein, ceruloplasmin, fibrinogen, and alpha₁-antitrypsin, has been demonstrated (4). Studies in subjects on long-term physical training showed chronic depression of plasma iron (5) and zinc (6) levels. Even frank anemia has been reported in joggers and competition runners (5). Cannon and Kruger were the first to relate this metabolic pattern, which displays a remarkable similarity to the physiological response to an infectious or inflammatory challenge, to an increased release of endogenous pyrogen, which is secreted by monocytes and macrophages (7).