Effect of IL-6 blockade and IL-6 administration on lung alveolar barrier albumin flux in VILI. A, IL-6-blocking Ab (2.66 mg/kg i.v.) (IL6AB) resulted in significantly higher alveolar barrier protein permeability compared with isotype control Ab-treated mice (CAB) (*, p < 0.05; n = 6 in each group) as measured by albumin flux (expressed as the percentage of vascular volume in the extravascular spaces of the lung, EVP%) in the VILI model. Pretreatment with rmIL-6 significantly reduced albumin flux (n = 7; **, p < 0.05) compared with untreated WT controls (n = 9). B, The wet:dry lung weight ratio was significantly higher in IL-6-blocking Ab-treated mice compared with control Ab-treated mice (*, p < 0.05).