In-vitro study of the effect of adrenaline on the functional capacity of human neutrophils: role during exercise

We studied the effect of adrenaline on the capacity of human neutrophils to attach, ingest and destroy Candida albicans. The neutrophils were incubated in vitro in the presence of an adrenaline concentration taken as basal (10-10 m), and another that is referred to as being reached following physical exercise (10-9 m). Two higher concentrations (10-7 m and 10-5 m), which are seldom attained in blood but which can occur at specific locations in the organism, were tested as having a possible pharmacological application. At the two high concentrations (10-7 m and 10-5 m), the capacity to attach, ingest and destroy C. albicans was greater than at the physiological concentrations (10-10 m and 10-9 m). Indeed, the capacity to attach and ingest C. albicans was significantly less after incubation with these physiological concentrations than the control values (incubation in the absence of adrenaline). Hence, high concentrations of adrenaline seem to enhance neutrophils' phagocytic capacity compared to physiological plasma concentrations, whereas small variations such as those caused by physical exercise have no effect on this functional capacity.