Enoximone maintains intestinal villus blood flow during endotoxemia.
The objective of this study was to determine the effects of a continuous infusion of the phosphodiesterase inhibitor enoximone on mucosal villus blood flow in a normotensive model of endotoxemia. Twenty-four anesthetized and ventilated rats underwent laparotomy and a ileal portion was exteriorized and opened by an antimesenteric incision. The ileal segment was fixed on a plexiglass stage with the mucosal surface upward. Microcirculatory parameters were assessed by intravital videomicroscopy. The animals were randomly assigned to receive one of three treatments: infusion of Escherichia coli lipopolysaccharides (LPS, 2 mg/kg/h) without phosphodiesterase inhibitor pretreatment (LPS group); or infusion of LPS with enoximone pretreatment (10 microg x kg(-1) x min(-1), start 30 min before LPS infusion, enoximone group), or infusion of an eqivalent volume of NaCl 0.9% (control group). Macrohemodynamic parameters (MAP, HR) and microhemodynamic parameters of ileal mucosa (mean diameter of central arterioles = DA, and mean erythrocyte velocity within the arterioles = VE) were measured 30 min before and at 0, 60, and 120 min after induction of endotoxemia. Mucosal villus blood flow was calculated from DA and VE. In this normotensive endotoxemia model MAP remained stable in the control and the LPS group but significantly decreased in the enoximone group. The endotoxin-induced decrease of VE and DE of central arterioles of mucosal villi could be prevented. Thus, mucosal villus blood flow did not decrease compared to the LPS group. Our results indicate that enoximone during an early stage of sepsis contributes to systemic hypotension but prevents mucosal hypoperfusion.