Differential inducible nitric oxide synthase activity in circulating neutrophils vs. mononuclears of septic shock patients.
OBJECTIVE
To compare nitric oxide synthase (NOS) activity in circulating neutrophils and mononuclear cells of patients with septic shock to healthy subjects.


METHODS
Prospective study in the general intensive care unit (30 beds) of a university affiliated-hospital and the A.C. Burton Vascular Biology Research Laboratory.


METHODS
Six septic patients and seven healthy volunteers.


RESULTS
We measured NOS in circulating neutrophils and mononuclears. Constitutive (cNOS) and inducible (iNOS) activities were analyzed by the [3H]L-arginine-L-citrulline assay. Plasma NOx- was determined by chemiluminescence. NOx- was higher in septic vs. controls (median 110, IQR 39-250 vs. 23, 14-46 microM; p<0.05). cNOS in septic cells was unmeasurable. iNOS in septic neutrophils was higher (median 34.9, IQR 10.4-95.8 vs. controls 2.5, 0-2.7 U; p<0.05) while iNOS in septic mononuclears was unaltered (median 16.4, IQR 9.1-52.6 vs. controls 8.9, 5.9-20.3 U; p=0.240).


CONCLUSIONS
Increased iNOS activity was found in circulating neutrophils of septic shock patients compared to healthy volunteers. Moreover, differential iNOS activity was evident in circulating neutrophils vs. mononuclears of patients with septic shock. Further investigations are warranted to confirm this differential iNOS activity and to explore its significance.
Hersch
Moshe
M
Intensive Care Unit, Shaare Zedek Medical Centre, 91301 Jerusalem, Israel. hersch@szmc.org.il
Scott
Jeremy A
JA
Izbicki
Gabriel
G
McCormack
David
D
Cepinkas
Gedeminas
G
Ostermann
Marlies
M
Sibbald
William J
WJ
D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D007963:Leukocytes, Mononuclear / Q000201:enzymology*; D009504:Neutrophils / Q000201:enzymology*; D009566:Nitrates / Q000097:blood; D052247:Nitric Oxide Synthase Type II / Q000097:blood*; D009573:Nitrites / Q000097:blood; D011446:Prospective Studies; D012772:Shock, Septic / Q000097:blood* / Q000201:enzymology
D009566:Nitrates; D009573:Nitrites; D052247:Nitric Oxide Synthase Type II