TNF-alpha alters nitric oxide- and endothelium-derived hyperpolarizing factor-mediated vasodilatation in human omental arteries.

OBJECTIVE

To investigate the effect of TNF-alpha on the endothelial function of human systemic arteries.

METHODS

Omental arteries were obtained from healthy pregnant women undergoing Cesarean section and examined using isometric wire myography.

RESULTS

Incubation with TNF-alpha (1nM) alone did not alter bradykinin-mediated endothelium-dependent relaxation of arteries. However, TNF-alpha did attenuate nitric oxide- (NO) and prostacyclin-independent endothelial-mediated relaxation. Similarly, in vessels constricted with a high potassium solution (60 mM), which inhibits vasodilatation via endothelial-derived hyperpolarising factor (EDHF), TNF-alpha incubation also attenuated bradykinin-induced vasodilatation.

CONCLUSIONS

The vasorelaxant capacity of human systemic arteries is compromised by TNF-alpha incubation in the presence of NO/prostacyclin or EDHF-blockade.