Braguini Welligton L, Cadena Silvia M S C, Carnieri Eva G S, Rocha Maria Eliane M, de Oliveira Maria Benigna M
Department of Biochemistry and Molecular Biology, Federal University of Paraná, C.P. 19046, C.E.P. 81531-990, Curitiba, Paraná, Brazil.
Toxicol Lett. 2004 Sep 25;152(3):191-202. doi: 10.1016/j.toxlet.2004.03.017.
Deltamethrin (DTM) is a synthetic pyrethroid insecticide used wideworld in agriculture, home pest control, protection of foodstuff, and disease vector control. It has widespread applications in Brazilian agriculture. The effects of DTM on mitochondrial respiratory parameters and on the organization of artificial and native membranes are described. DTM (200 nmol mg(-1) protein) on isolated liver mitochondria decreased oxygen consumption of both, state III and state IV, as well as the inner mitochondrial membrane potential (Deltapsi). Analysis of segments of the respiratory chain suggested that the DTM inhibition site is located between complex II and complex III. Mitochondrial swelling, energized or driven by the K+ diffusion potential using valinomycin, were partially inhibited by DTM (200 nmol mg(-1) protein). Fluorescence polarization of DPH and DPH-PA, probing the core and outer regions, respectively, of dimyristoylphosphatidylcholine (DMPC) and native mitochondrial membranes, indicated that DTM shifts the midpoint phase transition to lower values, besides broadening the phase transition. DTM decreased the lipid order of DMPC bilayers, at temperatures lower than the transition temperature and also caused a disordering effect on native membranes. However at temperatures above the transition temperature, the pesticide increased the rigidity of the membrane. These results suggest that DTM causes perturbations in lipid-lipid and lipid-protein interactions, interferes in transport mechanisms operating at the membrane level, and causes alterations of membrane permeability and mitochondrial enzyme activities. These effects could be associated with the toxicity of deltamethrin.
溴氰菊酯（DTM）是一种合成拟除虫菊酯类杀虫剂，在全球范围内广泛用于农业、家庭害虫防治、食品保护和病媒控制。它在巴西农业中有广泛应用。本文描述了DTM对线粒体呼吸参数以及人工膜和天然膜结构的影响。200 nmol mg(-1)蛋白质的DTM作用于分离的肝线粒体时，会降低状态III和状态IV的氧气消耗以及线粒体内膜电位（Δψ）。对呼吸链各部分的分析表明，DTM的抑制位点位于复合物II和复合物III之间。使用缬氨霉素，由K+扩散电位激发或驱动的线粒体肿胀会被200 nmol mg(-1)蛋白质的DTM部分抑制。分别探测二肉豆蔻酰磷脂酰胆碱（DMPC）核心区域和外层区域以及天然线粒体膜的DPH和DPH-PA的荧光偏振表明，DTM除了拓宽相变范围外，还会将相变中点移至更低值。在低于转变温度的温度下，DTM降低了DMPC双层膜的脂质有序性，并且对天然膜也产生了无序化作用。然而，在高于转变温度的温度下，该农药增加了膜的刚性。这些结果表明，DTM会导致脂质-脂质和脂质-蛋白质相互作用受到干扰，影响在膜水平上运行的转运机制，并导致膜通透性和线粒体酶活性发生改变。这些效应可能与溴氰菊酯的毒性有关。
