Effects of nimesulide, a selective cyclooxygenase-2 inhibitor, on cardiovascular alterations in endotoxemia

Prostanoids and cytokines are known to play a pivotal role in the mechanisms leading to endotoxin-induced cardiovascular failure. We investigated the effect of nimesulide (NIM), a selective cyclooxygenase-2 (COX-2) inhibitor, on the cardiovascular alterations occurring during endotoxemia, and on prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels in endotoxemic rats. NIM significantly reduced endotoxin-induced elevation of plasma and myocardial levels of TNF-α, but not those of IL-1β. Searching for the mechanism underlying the anti-TNF-α effect of NIM, it was found that the drug reduced nuclear factor kappa B activation through diminished nuclear levels of p-65 accompanied by a protective effect against the cardiovascular alterations and mortality seen during endotoxemia. In addition, the inhibitory effect of NIM on endotoxin-induced elevation in plasma and hypothalamic levels of PGE ₂ was noteworthy, and this may suggest that the large amounts of PGE₂ observed during endotoxemia are mainly produced via COX-2.