Effect of the nitric oxide inhibitor, L-N(G)-monomethylarginine, on accumulation of interleukin-6 and interleukin-8, and nuclear factor-kappaB activity in a human endothelial cell line.
OBJECTIVE
To determine the effect of the nitric oxide synthase inhibitor, L-N(G)-monomethylarginine, on interleukin-6 and interleukin-8 accumulation, and nuclear factor-kappaB expression in an endothelial cell model of sepsis.


METHODS
Controlled cell culture experiments examining the immunomodulatory effects of nitric oxide synthase inhibition.


METHODS
A human endothelial cell line (EA.hy926).


RESULTS
Cells were incubated with tumor necrosis factor-alpha and interleukin (IL)-1beta in the presence of L-N(G)-monomethylarginine (L-NMMA). IL-6 and IL-8 were measured in culture supernatants using enzyme immunoassay. Nuclear factor-kappaB was measured using electrophoretic mobility shift assay and was quantified using phosphorimaging. IL-6 accumulation was decreased (p < .05) and IL-8 accumulation increased (p < .01) with L-NMMA. Increased nuclear factor-kappaB expression in stimulated cells was unaltered on exposure to L-NMMA. Cell viability was unaffected.


CONCLUSIONS
Excessive production of nitric oxide has been implicated in septic shock, and the use of nitric oxide synthase inhibitors has been suggested. The immunoregulatory actions of nitric oxide synthase inhibitors affects the profile of cytokine release. This effect is not mediated through modulation of nuclear factor-kappaB. These findings have implications for the use of nitric oxide synthase inhibiting agents in septic shock.
Galley
H F
HF
Academic Unit of Anaesthesia and Intensive Care, Institute of Medical Sciences, University of Aberdeen, Foresterhill, UK.
Nelson
S J
SJ
Dhillon
J
J
Dubbels
A M
AM
Webster
N R
NR
D002460:Cell Line; D003470:Culture Media; D004353:Drug Evaluation, Preclinical; D004727:Endothelium / Q000166:cytology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000032:analysis*; D016209:Interleukin-8 / Q000032:analysis*; D016328:NF-kappa B / Q000032:analysis* / Q000187:drug effects*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D012772:Shock, Septic / Q000188:drug therapy / Q000201:enzymology / Q000276:immunology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology*
D003470:Culture Media; D007375:Interleukin-1; D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D019323:omega-N-Methylarginine; D019001:Nitric Oxide Synthase