Nitric oxide synthesis in patients with infective gastroenteritis.
BACKGROUND
There is evidence that endogenous nitrate synthesis is notably increased in patients with infective gastroenteritis.


OBJECTIVE
To determine whether this is due to nitric oxide (NO) production via the L-arginine/NO pathway.


METHODS
Seven male patients with community acquired bacterial gastroenteritis and 15 healthy male volunteers participated in this study. All patients had stool culture positive infective gastroenteritis. A bolus of 200 mg L-[(15)N](2)-arginine was administered intravenously after an overnight fast. Urine was collected for the next 36 hours. Urinary [(15)N:(14)N]nitrate ratio was assessed by dry combustion in an isotope ratio mass spectrometer.


RESULTS
Mean 36 hour total urinary nitrate excretion in the gastroenteritis group was 5157 (577) micromol compared with 2594 (234) micromol in the control group (p<0.001). Thirty six hour urinary [(15)N]nitrate excretion was considerably higher in the gastroenteritis group compared with the control group (13782 (1665) versus 1698 (98) etamol; p<0.001). These values represent 1.129 (0.139)% and 0.138 (0.007)% of [(15)N]nitrogen administered (p<0.001), respectively. Corrected 36 hour urinary [(15)N]nitrate excretion for urinary creatinine was also significantly higher in the patient compared with the control group (1934 (221) versus 303 (35) etamol/mmol; p<0.001).


CONCLUSIONS
Results show notably enhanced nitrate synthesis due to increased activity of the L-arginine/NO pathway in patients with infective gastroenteritis.
Forte
P
P
Department of Clinical Pharmacology, St Bartholomew's and the Royal London School of Medicine and Dentistry, London, UK.
Dykhuizen
R S
RS
Milne
E
E
McKenzie
A
A
Smith
C C
CC
Benjamin
N
N
D000328:Adult; D001120:Arginine / Q000378:metabolism*; D001424:Bacterial Infections / Q000378:metabolism*; D005759:Gastroenteritis / Q000378:metabolism*; D006801:Humans; D008297:Male; D017942:Nitric Acid / Q000652:urine; D009569:Nitric Oxide / Q000096:biosynthesis*; D009587:Nitrogen Isotopes
D009587:Nitrogen Isotopes; D009569:Nitric Oxide; D017942:Nitric Acid; D001120:Arginine