Supplements of L-arginine attenuate the effects of high-fat meal on endothelial function and oxidative stress.
BACKGROUND
Postprandial hypertriglyceridemia is known to cause endothelial dysfunction and increased oxidative stress. Oral supplements of l-arginine have been found to improve endothelial function. However, the effects of supplements of l-arginine on the influences of postprandial hypertriglyceridemia were not studied before.


METHODS
Forty young healthy men without any risk factors were equally divided into two groups. l-arginine group (age 22+/-1 years, body mass index 23.5+/-1.2 kg/m(2)) received a standard high-fat meal with 15 g oral l-arginine. Control group (age 22+/-1 years, body mass index 23.8+/-0.9 kg/m(2)) received a standard high-fat meal with placebo. A standard high-fat meal consisted of 900 kcal and 50 g of fat. Flow-mediated vasodilation (FMD), von Willebrand factor (vWF), p-Selectin, and glutathione peroxidase (GSH-Px) were measured before and 2 h after the high-fat meal.


RESULTS
Serum triglyceride levels were significantly increased 2 h after the high-fat meal in both groups. In the control group, FMD (10.5+/-1.2% vs. 6.8+/-1.4%, p<0.001) and GSH-Px (23.5+/-6.2 vs. 21.9+/-5.0 mug/ml, p=0.029) were significantly decreased after the high-fat meal. P-Selectin (20.0+/-7.7 vs. 25.9+/-10.5 mg/l, p=0.025) and vWF (731.2+/-131.5 vs. 934.9+/-133.8 mU/ml, p<0.001) were significantly increased after the high-fat meal. In the l-arginine group, FMD (10.3+/-1.3 vs. 9.3+/-0.9%, p<0.001) was slightly but significantly decreased after the high-fat meal but not GSH-Px (23.6+/-3.6 vs. 23.0+/-4.8%, p=0.468). P-Selectin (20.1+/-5.9 vs. 25.7+/-10.2 mg/l, p=0.001) and vWF (793.2+/-146.0 vs. 944.4+/-136.8 mU/ml, p<0.001) were significantly increased after the high-fat meal. Degree of FMD attenuation following the high-fat meal was significantly less in the l-arginine group (1.0+/-0.9 vs. 3.8+/-1.5%, p<0.001).


CONCLUSIONS
Concomitant supplements of l-arginine improved endothelial dysfunction and oxidative stress induced by postprandial hypertriglyceridemia. However, changes of p-Selectin and vWF were not affected by supplements of l-arginine with the high-fat meal.
Lin
Chih-Chan
CC
Department of Internal Medicine, National Cheng Kung University Hospital, Dou-Liou Branch, Dou-Liou, Taiwan.
Tsai
Wei-Chuan
WC
Chen
Ju-Yi
JY
Li
Yi-Heng
YH
Lin
Li-Jen
LJ
Chen
Jyh-Hong
JH
D000328:Adult; D001120:Arginine / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage* / Q000009:adverse effects; D019587:Dietary Supplements; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood / Q000517:prevention & control; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D019518:Postprandial Period / Q000187:drug effects / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D004041:Dietary Fats; D001120:Arginine