Blood serum and neutrophil L-arginine concentrations and nitric oxide release by neutrophils in chronic uremic patients and healthy persons.
BACKGROUND
Plasma levels of L-arginine have previously been evaluated in several studies to reveal either down- or up-regulation of the L-arginine/NO pathway in chronic uremia.


METHODS
We studied L-arginine plasma levels along with intracellular neutrophil concentration and NO release by peripheral blood neutrophils in patients with chronic uremia.


RESULTS
The L-arginine plasma concentration was found to be significantly higher (64.4 +/- 12.0 micromol/L) in chronic uremic patients (n=25) than in healthy controls (33.0? +/- 10.0 micromol/L; n=25). Neutrophil homogenate L-arginine levels were substantially increased in uremic patients (7.95? +/- 1.10 nmol/10(8) cells) as compared with controls (5.22 +/- 0.46 nmol/10(8) cells). The in vitro release of NO by unstimulated neutrophils was lower in uremic patients (0.14? +/- 0.05? micromol s(-1)) than in healthy persons (0.48 +/- 0.20 micromol s-1). The NO release after uremic neutrophil stimulation with 10(-6) M fMLP was 21.42 +/- 2.13 micromol s(-1), while after PMA it was 31.01 +/- 1.99 micromol s(-1). NO release after normal neutrophil stimulation with 10(-7) M fMLP was 19.52 +/- 2.32 micromol s(-1), and after PMA was 28.63 +/- 3.06 micromol s(-1).


CONCLUSIONS
In chronic uremic patients plasma and neutrophil concentrations of L-arginine were significantly higher. However, there were no significant differences in NO release between normal and uremic neutrophils after stimulation. Our findings may have implications for the impact of the L-arginine-nitric oxide signaling pathway on the pathophysiological changes in the L-arginine: NO pathway seen in chronic uremia.
Rysz
Jacek
J
2nd Department of Internal Medicine, Military Medical University, Łódź, Poland.
Guga
Piotr
P
Grycewicz
Tomasz
T
Mudyna
Janusz
J
Luciak
Marek
M
D000328:Adult; D001120:Arginine / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D014511:Uremia / Q000097:blood*
D009569:Nitric Oxide; D001120:Arginine