Liland Nina S, Simonsen Adam C, Duelund Lars, Torstensen Bente E, Berntssen Marc H G, Mouritsen Ole G
National Institute of Nutrition and Seafood Research (NIFES), P.O. Box 2029, Strandgaten 229, Bergen 5817, Norway.
MEMPHYS, University of Southern Denmark, Campusvej 55, Odense-M DK-5230, Denmark.
Chem Phys Lipids. 2014 Dec;184:18-24. doi: 10.1016/j.chemphyslip.2014.08.004. Epub 2014 Aug 30.
Polyaromatic hydrocarbons (PAHs) is a group of compounds, many of which are toxic, formed by incomplete combustion or thermal processing of organic material. They are highly lipophilic and thus present in some seed oils used for human consumption as well as being increasingly common in aquaculture diets due to inclusion of vegetable oils. Cytotoxic effects of PAHs have been thought to be partly due to a membrane perturbing effect of these compounds. A series of studies were here performed to examine the effects of three different PAHs (naphthalene, phenanthrene and benzo[a]pyrene) with different molecular sizes (two, three and five rings, respectively) and fat solubility (Kow 3.29, 4.53 and 6.04, respectively) on membrane models. The effects of PAHs on liquid-liquid phase coexistence in solid-supported lipid bilayers (dioleoylphosphocholine:dipalmitoylphosphatidylcholine:cholesterol) were assessed using fluorescence microscopy. Benzo[a]pyrene had a slight affinity for the liquid-ordered phase, but there were no effects of adding any of the other PAHs on the number or size of the liquid domains (liquid-ordered and liquid-disordered). Benzo[a]pyrene and phenanthrene, but not naphthalene, lowered the transition temperature (Tm) and the enthalpy (ΔH) characterising the transition from the solid to the liquid-crystalline phase in DPPC vesicles. The membrane effects of the PAH molecules are likely related to size, with bigger and more fat-soluble molecules having a fluidising effect when embedded in the membrane, possibly causing some of the observed toxic effects in fish exposed to these contaminants.
多环芳烃（PAHs）是一类化合物，其中许多具有毒性，由有机材料的不完全燃烧或热加工形成。它们具有高度亲脂性，因此存在于一些供人类食用的种子油中，并且由于植物油被纳入水产养殖饲料中，它们在水产养殖饲料中也越来越常见。PAHs的细胞毒性作用被认为部分归因于这些化合物的膜扰动效应。在此进行了一系列研究，以检查三种不同分子大小（分别为二环、三环和五环）和脂溶性（辛醇-水分配系数分别为3.29、4.53和6.04）的不同PAHs（萘、菲和苯并[a]芘）对膜模型的影响。使用荧光显微镜评估了PAHs对固体支持脂质双层（二油酰磷脂酰胆碱：二棕榈酰磷脂酰胆碱：胆固醇）中液-液相共存的影响。苯并[a]芘对液相有序相有轻微亲和力，但添加其他任何一种PAHs对液相区域（液相有序和液相无序）的数量或大小均无影响。苯并[a]芘和菲，而非萘，降低了表征DPPC囊泡从固态到液晶相转变的转变温度（Tm）和焓（ΔH）。PAH分子的膜效应可能与大小有关，更大且脂溶性更强的分子嵌入膜中时具有流化作用，这可能导致在接触这些污染物的鱼类中观察到的一些毒性效应。
