RESUMO
It is already shown that fasting has antiinflammatory, antitumor and antiageing effects, but the mechanisms responsible for these are still unclear. An increased oxidative stress is one of the common traits for inflammation, carcinogenesis and ageing, so it is a reasonable assumption to consider that fasting might act through influencing the oxidative status. In the present study we used three different respiratory burst activators (opsonized zymosan-OZ, phytohemagglutinin P-PHA, concanavalin A-Con A) in order to test whether fasting is able or not to change the free radical generation and associated chemiluminescence produced by polymorphonuclear leukocytes (PMNLs) of seven healthy human subjects. Fasting has induced a "spontaneous respiratory burst" of resting polymorphonuclear leukocytes, increasing the basal chemiluminescence of these cells and it has decreased the stimulatory index of leukocytes. In conclusion, fasting has a dual effect on the free radical generation of polymorphonuclear leukocytes.
