Amoxycillin/clavulanic acid combinations increase transmigration of leucocytes through endothelial cell monolayers: endothelial cells play a key role.

Postoperative inflammation is still viewed as an unresolved problem. During inflammation, leucocytes play a tremendous role and migrate from intravascular spaces into the tissue to attack microorganisms. Different agents, e.g. anaesthetic drugs, are able to influence leucocyte recruitment. Previous studies have investigated the influence of amoxycillin on chemotaxis of leucocytes alone. The aim of our study was to examine the effect of amoxycillin/clavulanic acid (co-amoxiclav) on leucocyte migration through endothelial cell monolayers (ECMs). Human umbilical endothelial cells were cultured on microporous membranes, achieving a monolayer. Polymorphonuclear neutrophil leucocytes (PMNLs) were used in a migration assay. The numbers of untreated PMNLs migrating through untreated ECMs were used as control and set as 100%. PMNLs and/or ECMs were pretreated with co-amoxiclav using clinically relevant as well as higher and lower concentrations. Co-amoxiclav was able to increase PMNL migration through ECMs significantly (P<0.05) when both cell types were treated (291+/-18.7%). When PMNLs or ECMs were treated alone, it could be shown that ECMs were more affected than PMNLs. The greatest effect was shown when both cell types, PMNLs and ECMs, were treated. In conclusion, co-amoxiclav was identified as a potent drug to increase leucocyte transmigration through ECMs. ECMs were also critically involved. Co-amoxiclav also affects endothelial cells.