Influence of amrinone on intestinal villus blood flow during endotoxemia

Purpose: The objective of this study was to determine the effects of a cont inuous infusion of the phosphodiesterase (PDE) inhibitor amrinone on mucosa l villus blood flow in a normotensive model of endotoxemia. Materials and Methods: Twenty-four anesthetized and ventilated rats underwe nt laparotomy, and an ileal portion was exteriorized and opened by an antim esenteric incision. The ileal segment was fixed on a plexiglass stage with the mucosal surface upward. Microcirculatory parameters were assessed by in travital videomicroscopy. The animals were randomly assigned to receive one of three treatments: infusion of Escherichia coil lipopolysaccharides (LPS , 2 mg/kg/h) without phosphodiesterase inhibitor pretreatment (LPS group); or infusion of LPS with amrinone pretreatment (40 mu g/kg/min, start 30 min utes before LPS infusion) (amrinone group), or infusion of eqivalent volume s of NaCl 0.9% (control group), Macrohemodynamic parameters (MAP, HR) and m icrohemodynamic parameters of ileal mucosa (mean diameter of central arteri oles = D-A and mean erythrocyte velocity within the arterioles = V-E) were measured 30 minutes before and at 0, 60, and 120 minutes after induction of endotoxemia. Mucosal villus blood flow was calculated from D-A and V-E. Results: In this normotensive endotoxemia model, MAP remained stable in the control and the LPS group but significantly decreased in the amrinone grou p. The endotoxin-induced decrease of V-E and D-A of central arterioles of m ucosal villi could be attenuated and prevented, respectively. Thus, the end otoxin-induced decrease of mucosal villus blood flow was diminished but not fully restored by amrinone infusion. Conclusion: Our results indicate that amrinone during an early stage of sep sis is of limited value. It attenuates mucosal hypoperfusion but contribute s to systemic hypotension. Copyright (C) 2000 by W.B. Saunders Company.