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Background: In view of the stimulatory effect of glucose on reactive oxygen species (ROS) generation, we investigated the possibility that a mixed meal stimulates ROS generation and possibly induces concomitant proinflammatory changes. Objective: The objective was to determine whether the intake of a 900-kcal mixed meal induces an increase in ROS generation by leukocytes and an inflammatory response at the cellular level. Design: Nine normal-weight subjects were given a 900-kcal mixed meal, and 8 normal-weight subjects were given 300 mL water after an overnight fast. Blood samples were collected at 0, 1, 2, and 3 h. ROS generation by mononuclear cells and polymorphonuclear leukocytes and the expression of [p47.sup.phox] subunit were measured. Intranuclear nuclear factor [kappa]B (NF-[kappa]B) binding and the expression of inhibitor [kappa]B[alpha] (I[kappa]B[alpha]), I[kappa]B kinase [alpha] (IKK[alpha]), and I[kappa]B kinase [beta] (IKK[beta]) were measured. Plasma concentrations of C-reactive protein (CRP) and soluble intercellular adhesion molecule were also measured. Results: ROS generation by mononuclear cells and polymorphonuclear leukocytes and [p47.sup.phox] expression increased significantly. The expression of IKK[alpha] and IKK[beta] and DNA-binding activity of NF-[kappa]B increased significantly, whereas I[kappa]B a expression decreased. Plasma CRP concentrations increased. The intake of 300 mL water did not induce a change in any of the above indexes. Conclusions: These data show that the intake of a mixed meal results in significant inflammatory changes characterized by a decrease in I[kappa]B[alpha] and an increase in NF-[kappa]B binding, plasma CRP, and the expression of IKK[alpha], IKK[beta], and [p47.sup.phox] subunit. These proinflammatory changes are probably relevant to the state of chronic hypertension and obesity and to its association with atherosclerosis. KEY WORDS Nuclear transcription factor [kappa]B, inhibitor [kappa]B, mononuclear cells, mixed meal, inflammation, reactive oxygen species

Background: It was recently shown that glucose challenge leads to increased generation of reactive oxygen species (ROS) by polymorphonuclear leukocytes (PMNs) and mononuclear cells (MNCs). Objective: To further elucidate the relation between nutrition and ROS generation, we investigated the effect of lipid and protein challenges on ROS generation by leukocytes. Design: After having fasted overnight, one group of healthy subjects consumed a carbohydrate- and protein-free cream preparation (1257 kJ) and another group of healthy subjects consumed an equienergetic pure preparation of casein. Sequential blood samples were obtained after the intake of cream and casein. ROS were measured by chemiluminescence after stimulation by N-formyl-methionyl-leucinyl-phenylalanine. Lipid peroxidation was measured as thiobarbituric acid-reactive substances (TBARS) and [alpha]-tocopherol was measured by HPLC. Results: ROS generation by MNCs and PMNs increased significantly 1, 2, and 3 h after cream intake and 1 h after protein intake. Cholesterol concentrations did not change significantly, whereas triacylglycerol concentrations increased significantly 2 h after cream intake. Total TBARS concentrations increased 1 h after cream intake and remained elevated 3 h after intake, but the increase was not significant when corrected for changes in triacylglycerol. After casein intake, total cholesterol, triacylglycerol, and TBARS concentrations did not change significantly, [alpha]-Tocopherol concentrations did not change significantly after either cream or casein intake. Conclusions: Both fat and protein intakes stimulate ROS generation. The increase in ROS generation lasted 3 h after cream intake and 1 h after protein intake. Cream intake also caused a significant and prolonged increase in lipid peroxidation. These data are important because increased ROS generation and lipid peroxidation are key events in atherogenesis. Am J Clin Nutr 2002;75:767-72. KEY WORDS Lipids, proteins, reactive oxygen species, leukocytes, lipid peroxidation, aging, thiobarbituric acid-reactive substances, TBARS, polymorphonuclear leukocytes, mononuclear cells, [alpha]-tocopherol

Intercellular adhesion molecule-1 (ICAM-1) is expressed by various cell types in human atherosclerotic lesions. It serves as a ligand for LFA-1 on leucocytes and is partially responsible for the adhesion [...]

Troglitazone has recently been shown to exert an antioxidant effect. To elucidate whether troglitazone exerts this effect through the inhibition of reactive oxygen species (ROS) generation by mononuclear cells (MNC) [...]

We have recently demonstrated that troglitazone administration into obese non-diabetic subjects: 1) inhibits reactive oxygen species generation by polymorphonuclear leucocytes and mononuclear cells ; 2) inhibits (9-HODE) and (13-HODE); 3) [...]

Periodontal disease, oral pathogenic bacteria, and microbial hard and soft tooth deposits are common risk factors for diabetic patients. The aim of this three month study was to evaluate the [...]

Oxygen free radical (OFR) generation by polymorphonuclear leukocytes (PMNL) is reduced following incubation with vitamin E in vitro. OFR damage amino acids in protein thereby altering the structure and function [...]

We have previously shown that reactive oxygen species (ROS) generation by mononuclear cells (MNC) in the obese is significantly greater than in normal subjects. To elucidate the relationship between nutrition [...]

Insulin is an arterial vasodilator in skeletal muscle vascular beds, and there is evidence that insulin mediated vasodilation is reduced in states of insulin resistance such as cancer, obesity and [...]