Disruption of endothelial barrier function: relationship to fluidity of membrane extracellular lamella.

1. Endothelial cells were cultured in tissue culture flasks or on microcarrier beads and labeled with a lipid specific spin-label. 2. Exposure of endothelial cells to benzyl alcohol caused a dose- and time-dependent increase in membrane fluidity using electron spin resonance (ESR). Maximum fluidity was reached after a 5-min exposure to 100 mM benzyl alcohol. 3. Albumin permeability across endothelial cells cultured on micropore filters was used as an indication of endothelial monolayer integrity. 4. A significant increase in permeability occurred with 50 mM benzyl alcohol. Maximal albumin permeability was reached after a 5-min exposure to 100 mM benzyl alcohol.