title: Increased phagocytic capacity of the blood, but decreased phagocytic activity per individual circulating neutrophil after an ultradistance run.
abstract: The effect of a long strenuous endurance exercise on the phagocytic function of neutrophils was examined. 9 athletes [7 males, 2 females, age: 36-68 years, body mass: 64 (SD 10) kg, height: 175 (SD 10) cm] completed a competetive 100 km run in 8:07 (median value; range: 7:29-9:50 hours). In a whole blood assay the phagocytosis of opsonized E. coli, the receptor density of the Fc gamma receptor 3 (CD16) and the complement receptor 3 (CD11b, direct immunofluorescence) of neutrophils were measured on a per cell basis by flow cytometry before and up to 3 hours after the race. The phagocytic rate (percentage of neutrophils incorporating bacteria) was unchanged after exercise, whereas the phagocytic activity (number of incorporated bacteria per cell) was significantly reduced by -34 (SD 8) % (Wilcoxon test, P < 0.001). The total phagocytic capacity of the blood increased 2-3fold post exercise. The surface antigen expressions of CD11b and CD16 were unaffected by the ultradistance run. The results indicate either a reduced phagocytic function of neutrophils on a single cell basis or the mobilization of neutrophils of the marginal pool with a lower phagocytic activity. However, after a long endurance exercise the phagocytotic capacity of the blood was enhanced due to increased cell concentrations.
authors.affiliation: Institute of Sports and Performance Medicine, University of Saarland, Saarbrücken, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Gabriel
authors.forename: H J
authors.initials: HJ
authors.lastname: Müller
authors.forename: K
authors.initials: K
authors.lastname: Kettler
authors.forename: L
authors.initials: L
authors.lastname: Brechtel
authors.forename: A
authors.initials: A
authors.lastname: Urhausen
authors.forename: W
authors.initials: W
authors.lastname: Kindermann
mesh_terms: D000328:Adult; D000368:Aged; D001790:Blood Physiological Phenomena; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology / Q000502:physiology*; D010587:Phagocytosis; D010807:Physical Endurance; D010953:Plasma Volume; D012420:Running