Inotropes inhibit endothelial cell surface adhesion molecules induced by interleukin-1 beta

Objectives: Leukocyte-endothelial cell interactions play a critical role in sepsis-induced multiple organ system failure and acute respiratory distress syndrome. Increased cyclic adenosine 3',5'-monophosphate (cAMP) has been previously reported to inhibit expression of the cytokine stimulated endothelial cell adhesion molecules, E-selectin, and vascular cell adhesion molecule-1 (VCAM-1). We hypothesized that clinically relevant concentrations of inotropes, such as amrinone and dopamine, which increase cAMP, could inhibit cytokine-stimulated upregulation of endothelial adhesion proteins. Design: Prospective, controlled in vitro study. Setting: Leukocyte biology laboratory. Subjects: Human umbilical vein endothelial cells isolated from neonatal umbilical cord specimens and whole blood obtained from normal human adult volunteers were used in this study. Interventions: Endothelial cell monolayers were pretreated with increasing concentrations of amrinone or dopamine, or left untreated as controls, followed by exposure to recombinant human interleukin (IL)-1 beta for 6 hrs. Monolayers were then incubated with monoclonal antibodies to E-selectin, VCAM-1, and intercellular adhesion molecule-1 (ICAM-1), fluorescence labeled, and assessed for mean fluorescence intensity by flow cytometry as a measure of surface adhesion molecule concentrations. Whole blood neutrophils were pretreated with or without inotropes, then stimulated with n-formyl methyl leucine phenylalanine. Stimulated neutrophils were incubated with antibodies against the neutrophil adherence protein CD11b and assessed by flow cytometry. Measurements and Main Results: IL-1 beta markedly increased E-selectin (p =.01), VCAM-1 (p < .01), and ICAM-1 (p <.001) concentrations (n = 6). Pretreatment with amrinone significantly decreased endothelial E-selectin surface Values at all concentrations (p < .001 by analysis of variance, n = 5), including therapeutic concentration ranges. Amrinone also inhibited upregulation of ICAM-1 (p <.001) at therapeutic concentrations, and VCAM-1 (p <.001) at higher concentrations. Dopamine inhibited only E-selectin at relevant concentrations. Neutrophil pretreatment with inotropes did not prevent CD11b upregulation. Conclusions: Pretreatment with amrinone, and to a lesser degree, with dopamine, at clinically relevant concentrations inhibits in vitro IL-1 alpha-induced increases in human umbilical Vein endo thelia[ cell adhesion molecule concentrations. Future studies are necessary to investigate the mechanisms of these effects and to determine in vivo efficacy of inotropes as anti-inflammatory agents.