SERUM CORTISOL ELEVATIONS AND LEUKOCYTE SUBSET CONCENTRATIONS AFTER ACUTE HEAVY RESISTANCE EXERCISE IN WOMEN

Abstract

116 Cortisol has been shown to cause neutrophilia, lymphocytopenia, and monocytopenia. However, few studies are available regarding the role of serum cortisol elevation in the immune system of women after resistance exercise. To examine the high (> 1000 nmol L−1) and low (< 500 nmol L−1) concentrations of serum cortisol for the leukocyte subset concentrations after acute heavy resistance exercise, eight high (23.5 ± 3.2 yrs) and eight low (22.1 ± 3.4 yrs) responders were studied from a population of 46 healthy, but non-strength trained women. The resistance test consisted of six sets of 10 RM squats with two minutes rest between sets utilizing a computerized Plyometric Power System. Blood samples were obtained at pre-exercise and immediately post-exercise. Serum cortisol was measured using an 125I solid-phase radioimmunoassay. Leukocyte subset proportions were measured by immunofluorescent staining with subset specific monoclonal antibodies and analyzed using flow cytometry. Results from a two-way ANOVA analysis indicated that the squat exercise significantly (p ≤ 0.05) increased lymphocyte, monocyte, and granulocyte concentrations of both groups. However, only granulocyte concentration of high cortisol group (pre: 4.88; post: 6.95: × 106 ml−1) was significantly greater than one of low cortisol group (pre: 3.69; post: 5.23: × 106 ml−1). Thus, the high cortisol levels may have played a role in the increased granulocyte concentration which could be related to muscle tissue damage and inflammation after acute heavy resistance exercise. Supported by DOD US Army Grant DAMD 17-95-C-5069 to WJK