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REDUCED GENERATION OF REACTIVE OXYGEN SPECIES BY CIRCULATING LYMPHOMONONUCLEAR CELLS AND AN ENDOTHELIAL CELLULAR MODEL IN THE POST-PRANDIAL STATE
Sodré F.L., Paim, B.A., Urban, A., Vercesi A.E., Faria E.C.
Department of Clinical Pathology, School of Medical Sciences, State University of Campinas, São Paulo, Brazil.
Objectives: To characterize changes in the cellular generation of reactive oxygen species (ROS) in healthy male during the post-prandial state, and to analyze the influence of post-prandial state on endothelial ROS generation.
Methods: Nineteen adult male volunteers (20-39y), without coronary heart disease or cardiovascular risk factors were recruited. Blood samples were collected from before and 2, 4, 6 and 8 hours after the intake of a liquid meal (25% fat, 55% dextromaltose, 14% protein) providing 40 g fat/m2 body surface. Monocytes and lymphocytes were separated by density gradient centrifugation and their viability tested in the trypan blue assay. Influence of post-prandial plasma samples on intracellular ROS generation in vitro was studied in cultured endothelial cells (EC-304). ROS were measured using flow cytometry as oxidation of dihydroethidium.
Results: Reduced generation of ROS was observed post-alimentary. ROS generation by lymphocytes from fasting plasma was higher as compared to those from post-prandial samples, p < 0.001. In parallel, ROS generation by monocytes from fasting plasma was also higher, p = 0.017. In EC-304 incubated with plasma samples, generation of ROS was negatively correlated with plasma total cholesterol, apo-B100, and LDL-cholesterol.
Conclusions: In contrast to previously reported elevation of oxidative stress during the post-prandial state in healthy individuals, this study shows reduced ROS generation in circulating lymphomononuclear cells. Data obtained in endothelial cells in vitro equally suggest an existence of a protective response against post-prandial oxidative stress.
Support: FAPESP
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