The effects of intense physical exercise on secondary antibody response inyoung and old mice

Background and Purpose. Based largely on data from young subjects, intense physical exercise is believed to suppress immune function. In addition, imm une function, including secondary antibody response, declines with advancin g age. Therefore, intense exercise in old subjects may further suppress the secondary antibody response. The purpose of this in vivo study was to inve stigate the effects of intense physical exercise on secondary antibody resp onse in young (6-8 weeks) and old (22-24 months) C57BL/6 mice. Subjects and Methods. Data were obtained from 22 young and 18 old C57BL/6 mice that wer e immunized to human serum albumin (HSA) and randomly divided into 3 groups . Two groups were exposed to a single bout of Intense exercise to exhaustio n and immediately boosted with an injection of HSA. The first group did not exercise further, but the second group continued with daily bouts of inten se exercise to exhaustion for 9 days. The third group (control group) did:n ot undergo intense exercise, but received the booster injection of HSA at t he same time as the other groups. Ten days after the HSA booster injection, when high level of antibodies are produced in secondary antibody response, serum anti-HSA antibodies were measured by enzyme-linked immunosorbent ass ay. Results. Young mice did not show suppression of secondary antibody resp onse following intense exercise. However, old mice, exposed to a single bou t of intense exercise, had an enhanced response similar to the response see n in young control mice. Conclusion and Discussion. The widely accepted hyp othesis of immunosuppression resulting from intense exercise may not be tru e for old mice.