HIGH SALT BUT NOT HYPEROSMOLARITY INDUCES A DELAYED ACTIVATION PATTERN IN HUMAN NEUTROPHILS

MAZZITELLI, IGNACIO; BLEICHMAR, LUCÍA; DIAZ, FERNANDO ERRA; MELUCCI GANZARAIN, CLAUDIA; GEFFNER, JORGE

Congreso; REUNIÓN CONJUNTA SAIC SAI & FAIC SAFIS 2022; 2022

Elevated concentrations of salt (NaCl) are present in a number of tis- sues under physiological and pathological conditions. We have pre- viously reported a paradoxical time-dependant effect of high NaCl (50 mM) on neutrophil function: an early paralysis followed by a delayed stimulation of neutrophil responses, such as IL-8 and ROS production. Here, we analyzed whether the effect induced by NaCl on neutrophil function was related to a direct action exerted by NaCl or to osmotic stress. Neutrophils were isolated from human blood by conventional procedures (purity >95%). Increasing osmolarity of the culture medium by the addition of sorbitol or mannitol (100 mM) was completely unable to stimulate neutrophil responses, suggesting that high sodium but not an increased osmolarity mediates the ac- tivation on neutrophil responses: production of IL-8 at 8 h of culture was 0±0, 4102±384, 0±0 and 0±0 (pg/ml), for neutrophils cultured in control medium or in the presence of medium supplemented with NaCl (50 mM), manitol (100 mM), or sorbitol (100 mM) (p 50, n=8). Interestingly we also observed that while phagocytosis of unopsonized-C. albicans was significantly inhibited by high salt (>72%, p