Correlation between fluidising effects on phospholipid membranes and mitochondrial respiration of propofol and p-nitrosophenol homologues

Nitrosopropofol (2-6-diisopropyl-4-nitrosophenol) has dramatic consequences for respiration, ATP synthesis and the transmembrane potential of isolated rat liver mitochondria at concentrations at which propofol (2-6-diisopropylphenol) does not cause any apparent effects. These results correlate well with the observation that nitrosopropofol is also a stronger perturbing agent of phospholipid membranes. In this paper we verify the possible biological activity of different phenols and nitrosophenols on mitochondrial respiration. We then discuss their interactions with phospholipid liposomes, studied with differential scanning calorimetry, spin labelling techniques and UV-Vis spectrophotometry, in order to obtain information on drug distribution and the modifications they impose on lipid bilayer. The results of the experiments performed on mitochondria and model membranes prove an interesting correlation between the effects of the molecules on both systems.