['it appears that hypertriglyceridemia (HTG) is a risk factor of atherosclerosis as demonstrated by recent studies. In this study, we analyzed the effects of acute HTG on endothelial function and oxidative stress, which are important mechanisms in the pathogenesis of atherosclerosis.', 'in a high fat meal group (n = 11), serum triglycerides and PMA-activated leukocyte O(2)(-)* production were significantly (P < 0.005) increased from 146 +/- 69 mg/dl and 4.09 +/- 0.93 nmol/10(6) cells/min preprandially to 198 +/- 88 mg/dl and 5.49 +/- 1.19 nmol/10(6) cells/min, respectively, 2 h after eating a high-fat meal. The flow-mediated endothelium-dependent brachial artery dilation (FMD; high-resolution ultrasound) was decreased from 13.7 +/- 3.3% preprandially to 8.2 +/- 3.7%, 2 h after eating a high-fat meal (P < 0.005). However, following a low-fat meal (n = 9), there were no significant changes in triglycerides, leukocyte O(2)(-)* production and FMD. Changes of serum triglycerides were correlated negatively (r = -0.650, P < 0.005) with changes of FMD, but were correlated positively (r = 0.798, P < 0.001) with changes of leukocyte O(2)(-)* production, which - in turn - were correlated negatively (r = -0.784, P < 0.001) with changes of FMD in all study subjects (mean age: 56 years, n = 20).'] Does postprandial hypertriglyceridemia impair endothelial function by enhanced oxidant stress?