FLOW-CYTOMETRIC ANALYSIS OF OXIDATIVE AND PROTEOLYTICAL ACTIVITIES INTISSUE-ASSOCIATED PHAGOCYTES FROM NORMAL AND HYPERTROPHIC MUSCLES

The study was conducted by the known tendencies of increased stress-su sceptibility and metabolic disorders in individuals with hypertrophied muscles due to innate factors or intensive exercise which can induce the overtraining syndrome. Using an animal model, muscle-associated ce lls from normal (N) and hypertrophic (H) skeletal muscle (m.semitendin osus) were examined in their resting and phorbolmyristate acetate (PMA ) stimulated oxidation of dihydrorhodamine (DHR) as well as cathepsin B and L activities. Phagocytes were phenotyped by their casein recepto rs (CR) and fibroblasts by their surface collagens (I and IV). The por tion of CR-cells in single cell suspension was 4-8% and 1-3% in H and N. The CR-cells were enriched by 200 g centrifugation and cultured for 5 days with and without cortisol (C), norepinephrine (NE) and indomet hacin (I). NE suppressed dose-dependently CR-expression in N, with inc rease in H occuring. C, NE and I elevated cathepsin activities only in N. PMA stimulated DHR oxidation in H and N 5- and 2-fold. Only the ox idative rate in N reacted to C, NE and I significantly. The data sugge st that the response of muscle-associated cells from hypertrophied and normal muscles to signals released in stress-coping significantly dif fers.