Superoxide production was studied in purified neutrophils of 122 healthy male humans aged from 18 yr to 79 yr to determine whether bacterial killing ability were altered by aging and daily exercise habit. Subjects were classified to 6 generation groups. Phorbol 12-myristate 13-acetate (PMA) -stimulated superoxide-generating activity of neutrophils was measured by the cytochrome c reduction assay. With respect to exercise habit and superoxide-generating activity, athletes between the ages of 18 and 24 who belonged in sport clubs of university (86.0±32.5 nmol/min/10⁷ cells), and people 25 and over doing regular exercise for health (73.8 ± 24.3 nmol/min/10⁷ cells) did not differ in age-matched counterparts (97.0±36.6 and 70.7±21.3 nmol/min/10⁷ cells), respectively. A significant negative correlation (-0.219) was found between age and superoxide-generating activity of neutrophils in all subjects. However, activity of the youngest generation (between 18 and 24 yr) denoted significantly higher than that of other generations. There was also no significant relationship between age and superoxide-generating activity of neutrophils in people 25 and over. It is suggested that neutrophils bacterial killing is not altered by exercise habit in any generation and by aging in people 25 and over, although young generation (18-24 yr) possesses specifically high superoxide-generating activity of neutrophils.

DESCENTE SPORTS SCIENCE Vol.26/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE