CHANGES WITH AGING, SEX AND PHYSICAL EXERCISE IN MURINE NATURAL-KILLER ACTIVITY AND ANTIBODY-DEPENDENT CELLULAR CYTOTOXICITY

Antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK ) activity were measured in leukocytes from the axillary nodes, the sp leen and the thymus of young (12 +/- 2 weeks) and aged (60 +/- 2 weeks ) male and female BALB/c mice, which had performed an acute bout of ex ercise (moderate swimming until exhaustion) or a training exercise (90 min of moderate swimming each day for 20 days). The results show that NK and ADCC activity in sedentary mice (controls) were similar in you ng and aged animals. However, both kinds of exercise resulted in highe r cytotoxicity values in aged mice than in young mice. Acute exercise did not have any effect on NK activity in young and aged mice, nor on ADCC activity in young mice as compared to controls, while training ex ercise stimulated both cytoxicities in the two age groups. No correlat ions between serum corticosterone levels and NK or ADCC activity were found. Our results suggest that moderate training exercise improves bo th NK and ADCC activity during aging.