Elusidation of the enhancing factor in paraquat toxicity under magnesium restriction

设计了一种高灵敏但简单的铜的定量方法(发表在《临床化学》，2001，《法医毒物杂志》，2001)。只需5μL的血浆或1.5ml的自来水就足以定量铜。用该方法测定了饲料中250ppm百草枯中毒大鼠的组织铜含量。采用岛津AA-6200原子吸收光谱仪测定铁、镁、锌的含量。中毒组大鼠肺、肝、血浆中铜含量增加2倍，肾中铜含量降低至0.5倍。肝脏和脾中铁含量增加2倍，血浆中铁含量降低0.5倍。肾脏中的镁含量增加了2倍。肝脏镁或锌显著增加(J Toxicol Envion Health，2002)服用125ppm百草枯的mg限制大鼠，这些矿物质也有相同的变化(JpnJ Legal Med，2001)。然而，在镁限制的大鼠中，肾脏中的钙增加了10倍(将在2002年第86届Jpn Soc Legal Med大会上报道)。仅限食镁通常需要35天以上的时间才能积累如此高的钙。限镁条件下饲喂125ppm的百草枯加速了百草枯中毒和镁缺乏。在所有矿物质限制下，喂食125ppm百草枯的大鼠肾脏钙增加到20倍，而饮食中的钙与镁的比例保持不变(将发表在Isalm，2002)。

A highly sensitive but simple method for the quantification of Cu was devised (published in Clin Chem, 2001, JpnJ Forensic Toxicol, 2001). Only 5μl of plasma or 1.5 ml of running water is enough to quantify Cu. By use of this method tissue Cu levels of rats intoxicated with paraquat at 250 ppm in the diet were examined. The contents of Fe, Mg and Zn were determined by atomic absorption spectrometry, Shimadsu AA-6200 which was obtained by the present Grant-in-Aid. In intoxicated rats, Cu increased 2-fold of the control in lung, liver or plasma, and decreased to 0.5-foldin kidney. Fe increased 2-fold in liver or spleen, and decreased to 0.5-fold in plasma. Mg increased 2-fold in kidney. Liver Mg or Zn increased significantly (J Toxicol Environ Health, 2002)Mg restricted rats dosed with 125 ppm paraquat gave the same changes in these minerals (JpnJ Legal Med, 2001). However, Ca in kidney increased 10-foldin Mg restricted rats (will be reportedinThe86th Congress ofJpn Soc Legal Med, 2002). Usually it takes more than 35days to accumulate Ca at such a high level by dietary Mg restriction only. Feeding paraquat at 125 ppm under Mg restriction accelerated both paraquat toxicosis and Mg deficiency. The kidney Ca of rats fed with 125 ppm paraquat under all mineral restriction increased to 20-fold, where the ratio of Ca to Mg in the diet was maintained (will be reported in ISALM, 2002).