Knowles S O, Donaldson W E, Andrews J E
Department of Toxicology, North Carolina State University, Raleigh 27695, USA.
Biol Trace Elem Res. 1998 Feb;61(2):113-25. doi: 10.1007/BF02784024.
Chronic treatment with inorganic lead (Pb) has been shown to increase the proportion of arachidonic acid (ArA), as well as the arachidonate/linoleate (ArA/LA) ratio, in the fatty acids of lipids from a variety of avian tissues. Changes in two fatty acid-mediated phenomena, peroxidation of membrane lipids and synthesis of eicosanoid cytokines, are associated with this enhanced ArA content. The authors are not aware of any reports in the literature in which these effects of Pb have been described for any animals other than birds. In the current study, the authors investigated the effect of Pb on lipid metabolism in three species: avian, rodent, and human. The group of children identified as suffering environmental Pb exposure were from a Pb-surveillance program and had blood Pb concentrations (PbB) averaging 23 microg/dL. Turkey poults fed 100 ppm dietary Pb as Pb acetate-trihydrate for 19 d had a PbB of 46 microg/dL. Gastric intubation of rats with 80 mg Pb/kg/d for 10 d resulted in a PbB of 74 microg/dL. We analyzed fatty acid composition of whole blood from children, poults, and virgin rats. Low-dose (nongrowth inhibitory) Pb exposure resulted in significantly increased ArA concentration and ArA/LA ratio in blood from all species. Also analyzed were plasma and liver of poults, virgin rats, and pregnant rats and their fetuses. In plasma and liver from Pb-treated poults and virgin rats, ArA and the ArA/LA ratio were again enhanced. Pb intoxication also affected omega3 composition, increasing the concentrations of all long-chain omega3 fatty acids of fetuses from Pb-treated pregnant dams. The authors propose that altered fatty acid metabolism may be responsible for some indications of Pb poisoning. Possible consequences mediated through lipid peroxidation and production of ArA-derivative eicosanoids are considered.
无机铅（Pb）的长期治疗已表明，会增加多种禽类组织脂质脂肪酸中花生四烯酸（ArA）的比例以及花生四烯酸/亚油酸（ArA/LA）的比值。膜脂质过氧化和类二十烷酸细胞因子合成这两种脂肪酸介导的现象变化与这种ArA含量增加有关。作者尚未在文献中发现有任何关于除鸟类之外的其他动物中描述铅的这些作用的报告。在当前研究中，作者调查了铅对三种物种（禽类、啮齿动物和人类）脂质代谢的影响。被确定遭受环境铅暴露的儿童组来自一个铅监测项目，其血铅浓度（PbB）平均为23微克/分升。用100 ppm作为三水合醋酸铅的膳食铅喂养火鸡雏19天，其PbB为46微克/分升。以80毫克铅/千克/天的剂量给大鼠胃插管10天，导致PbB为74微克/分升。我们分析了儿童、火鸡雏和未生育大鼠全血的脂肪酸组成。低剂量（无生长抑制作用）的铅暴露导致所有物种血液中ArA浓度和ArA/LA比值显著增加。还分析了火鸡雏、未生育大鼠和怀孕大鼠及其胎儿的血浆和肝脏。在铅处理的火鸡雏和未生育大鼠的血浆和肝脏中，ArA和ArA/LA比值再次升高。铅中毒还影响ω-3成分，增加了铅处理的怀孕母鼠胎儿所有长链ω-3脂肪酸的浓度。作者提出，脂肪酸代谢改变可能是铅中毒某些表现的原因。考虑了通过脂质过氧化和ArA衍生类二十烷酸产生介导的可能后果。
