Electropermeabilization and electrofusion of human cells modified by anaesthetic agents

Results on the interaction between anaesthetics and human cell membranes ar e presented in order to show their target behavior including changes in ele ctropermeabilization and resealing. Using electroporation and electrofusion techniques, it is possible to characterize the effects of anaesthetic agen ts which act as modifiers of cell membrane permeability depending on their types, concentrations and contact times. The field-induced uptake of trypan blue, used as a reporter of membrane electropermeabilization, and electrof usion of human lymphoma cells U 937 and human breast cancer cells MCF 7 wer e investigated. The cell electropermeabilization decreased with increasing external medium conductivity and osmolarity. The resealing kinetics of both types of cells studied could be fitted by exponentially decaying curves, h owever the first order rate constant for lymphoma cells was about two order s of magnitude higher. Moreover, the resealing step was slowed down in the presence of anaesthetics. It is suggested that the impact of anaesthetics o n cell membranes may be explained by the combined action of different inter action mechanisms, electrical and/or mechanical in nature, as well as by sp ecific bindings to integral membrane molecules, depending on the anaestheti c agent applied. It is concluded that the influence of anaesthetics on in v itro cell electropermeabilization might be used as an additional indicator for clinical purposes. (C) 1998 Elsevier Science S.A. All rights reserved.