Lipids perfluorinated

The concentrations of PFAs in environments have increased sharply over time (Holmstrom et al., 2005). The sorption/accumulation and fate of PFAs differ from classical chlorinated and brominated POPs in that perfluorinated molecules have surfactant characteristics (i.e., having polar and nonpolar domains) and oleophobic properties. Thus, PFAs is likely to bind to serum protein rather than lipid in tissues (Jones et al., 2003). 

An intermediate phase of tetragonal syiiunetry - the T phase - has also been detected in a number of systems. A rod structure related to a square mesh surface was foimd to agree well with X-ray and NMR data on a perfluorinated surfactant-water mixture forming the T phase [22], [34]. These examples demonstrate that surfactant or lipid monolayers lining mesh surfaces as well and bilayers wrapped onto three-periodic minimal surfaces (IPMS) are indeed found in these self-assembled systems. 

The correlation between anaesthetic potency and lipid solubility shown in Fig. 2.10 is valid for most inhaled anaesthetics and the product MAC X oil/gas partition coefficient (which should of course be a constant) varies by only a factor of 2 or 3 for potencies ranging over 100 000-fold. This constancy implies that inhaled anaesthetics act in the same manner at a specific hydrophobic site (the so-called unitary theory of anaesthesia). This has been challenged by more recent work that has identified compounds, including alkanes and poly-halogenated and perfluorinated compounds, which do not obey the Meyer- Overton hypothesis. It has been suggested that a contributory cause of deviation from this hypothesis may be the choice of lipid to represent the anaesthetic site of action of these compounds, implying that there may be multiple sites of action for inhaled anaesthetics. 

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