Effect of amino acids on mesenteric blood flow in humans.
BACKGROUND
Intraluminal nutrients increase superior mesenteric artery (SMA) blood flow. Little is known about the effect of circulating nutrients.


METHODS
The effect of a commercially available mixed amino acids solution, given either intravenously (IVAA) or intraduodenally (IDAA), on SMA hemodynamics was investigated in five healthy volunteers (three men, two women; 20-30 years old). Amino acids were given at a rate of 250 mg protein/kg/h for 2 h. Saline was used as control solution. Doppler ultrasound measurements of SMA hemodynamics were performed after 0, 30, 60, and 120 min.


RESULTS
IVAA had no significant effect on SMA hemodynamics. In contrast, IDAA significantly (P < 0.05) increased SMA flow volume by 60-80% over basal and the IVAA experiment. This increase in SMA flow volume during IDAA resulted primarily from a significant (P < 0.05) increase in time-averaged velocity. During IDAA both the peak systolic velocity and the end-diastolic velocity increased significantly (P < 0.05).


CONCLUSIONS
In healthy subjects intraduodenal, but not intravenous, amino acids significantly increase SMA blood flow.
Gielkens
H A
HA
Dept. of Gastroenterology-Hepatology, Leiden University Medical Center, The Netherlands.
van Oostayen
J A
JA
Onkenhout
W
W
Lamers
C B
CB
Masclee
A A
AA
D000328:Adult; D000596:Amino Acids / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology*; D002766:Cholecystokinin / Q000097:blood; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D017538:Mesenteric Artery, Superior / Q000187:drug effects / Q000502:physiology*
D000596:Amino Acids; D002766:Cholecystokinin