Altogether, this suggests that simvastatin, especially if given prior to LPS, might have a hepatoprotective activity in endotoxemia.
Bioactive Compound Library price LPS increased liver nitro-oxidative stress, shown by an increase in nitrotyrosinated proteins. Simvastatin abrogated the increase in nitrotyrosinated proteins when given prior to or after LPS (Fig. 5A). This could not be explained by a reduction in the iNOS expression, suggesting that simvastatin attenuated nitrosative stress by reducing the generation of reactive oxygen species. Indeed, the increase in liver 4-hydorxynonenal (4-HNE) immunostaining (as a marker of oxidative stress) induced by LPS was blunted by simvastatin treatment, given before or after LPS (Fig. 5B). This study shows that LPS administration induces microvascular dysfunction in rat livers, manifested by increased intrahepatic resistance and by decreased vasodilatory response of the liver circulation to acetylcholine, the hallmark of endothelial dysfunction. This microvascular dysfunction was fully developed 24 hours after LPS challenge. We further demonstrate here that prophylactic simvastatin, a drug that has been shown to correct both systemic and hepatic endothelial dysfunction,24, 25 prevents the development
of microvascular Cilomilast dysfunction and attenuates liver inflammation and liver injury induced by endotoxemia. These findings suggest that the potential of statins for the prevention of liver injury during sepsis should be further explored. medchemexpress The occurrence of impaired organ perfusion is the key point for prognostic changes of patients with sepsis.2 In vitro, ex vivo, and in vivo studies have clearly demonstrated that endothelial dysfunction occurs at the level of microcirculation of several organs, i.e., heart, lung, brain, kidney, similar to what occurs at the
level of conductance vessels.4 Our study exhaustively explored endothelial function at hepatic microcirculation in a model of endotoxemia. Our model of isolated liver perfusion allows evaluating specifically the changes occurring at the liver microcirculation, without the interference of the well-described events occurring upstream of the liver, at the systemic and splanchnic circulation (decreased systemic and splanchnic resistance and increased cardiac output30). We demonstrate the presence of sinusoidal endothelial dysfunction after LPS, which may be determinant to explain the decrease in liver blood flow after LPS challenge described by other authors.31 From a molecular point of view previous reports have shown that, similar to nonhepatic endothelial cells, sinusoidal endothelial cells exposed to LPS exhibit decreased eNOS activation through decreased phosphorylation at Ser1176.12 The present study shows that this also occurs in a complex in vivo model, where LPS administration was associated with decreased liver Ser1176 eNOS phosphorylation.