[Lipid pore states in bilayer lipid membranes at phase transition in LiCl solution with addition of polyethylene glycols].

Statistics on open and closed states of the lipid pores was experimentally investigated in planar lipid bilayer membranes from dipalmitoylphosphatidylcholine at the phase transition temperature in LiCl solution (1 M). Polyethylene glycol of different molecular mass was added to the solution. Transmembrane current pulses were measured at voltage-clamp conditions (50 mV). The histograms of the pore lifetime and the pulse interval have no exponential shape but the pronounced maximum. It means that the pulse sequence of the transmembrane current measured in the phase conditions is dependent. The emergence of the new pulses depends on the emergence time of the previous pulses. The time of the pulse end depends on the time of the pulse start. The proposed Erlang model approximates the experimental histograms quite accurately. According to the model the lipid pore can have several open and closed states.