Addition of 2.5 g L-arginine in a fatty meal prevents the lipemia-induced endothelial dysfunction in healthy volunteers.
BACKGROUND
Endothelial function as determined by flow-mediated dilation (FMD) deteriorates during postprandial lipemia. The impairment can be neutralized by adding 50 g casein to the fatty meal. The objective of this study was to see which of the casein constituents is responsible for this neutralization effect.


METHODS
A crossover design was used in 15 healthy volunteers, who were given 3 ml cream/kg body weight with and without 2.5 g L-arginine. Lipids and FMD were then determined hourly over a period of 6h. In substudies this design was repeated with 2.5 g phenylalanine and 5 g leucine in 11 subjects. The effect of 2.5 g L-arginine on FMD in the absence of cream was tested in seven subjects.


RESULTS
Without L-arginine the FMD deteriorated during 4h after the fat loading. Addition of L-arginine prevented this deterioration at 3 and 4h. Phenylalanine and leucine, in contrast, did not prevent the lipemic endothelial dysfunction. L-Arginine alone similarly had no acute effect on the FMD.


CONCLUSIONS
2.5 g L-arginine, but not phenyalanine or leucine, is able to prevent the lipemic dysfunction of the endothelium.
Borucki
Katrin
K
Institute of Clinical Chemistry, Magdeburg University Hospital, Magdeburg, Germany. katrin.borucki@med.ovgu.de
Aronica
Steffi
S
Starke
Irmgard
I
Luley
Claus
C
Westphal
Sabine
S
D000328:Adult; D001120:Arginine / Q000494:pharmacology*; D001835:Body Weight; D002364:Caseins / Q000737:chemistry; D018592:Cross-Over Studies; D004041:Dietary Fats; D004730:Endothelium, Vascular / Q000473:pathology*; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000150:complications*; D007700:Kinetics; D008055:Lipids / Q000737:chemistry; D008297:Male; D019518:Postprandial Period / Q000187:drug effects; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects
D002364:Caseins; D004041:Dietary Fats; D008055:Lipids; D001120:Arginine