Splenic immune responses following treadmill exercise in mice

Area of Science:

• Immunology
• Exercise Physiology
• Cellular Biology

Background:

• Exercise influences immune function, but the specific effects of training versus acute exercise on splenic lymphocytes are complex.
• Understanding exercise-induced immunomodulation is crucial for optimizing training protocols and immune health.

Purpose of the Study:

• To investigate the impact of an 8-week treadmill training program and a single bout of exhaustive exercise on splenic lymphocyte proliferation in C57BL/6J mice.
• To assess changes in total splenic lymphocyte numbers and plasma corticosterone levels in response to exercise.
• To determine the relationship between exercise-induced immunomodulation and adrenocortical activation.

Main Methods:

• Mice underwent an 8-week treadmill training program or a single exhaustive exercise session.
• Splenic lymphocyte proliferation responses to lipopolysaccharide and pokeweed mitogen were measured.
• Total splenic mononuclear cell counts and plasma corticosterone levels were analyzed.

Main Results:

• Trained mice exhibited enhanced splenic lymphocyte proliferation 72 hours post-training compared to sedentary controls.
• Immediate post-exercise lymphocyte proliferation was suppressed, and total splenic mononuclear cell counts were reduced.
• Plasma corticosterone levels did not show a clear association with exercise-induced immune changes.

Conclusions:

• Moderate endurance training augments splenic B lymphocyte mitogenesis.
• The immediate effects of exercise on splenic immune function are dependent on exercise duration and intensity.
• Exercise-induced immunomodulation is not solely explained by changes in plasma corticosterone levels.