Analysis of poisons by using electron spin resonance method

电子自旋共振是一种仅检测不成对电子（自由基）的灵敏方法。通过使用这种方法，可以准确测量血浆和组织匀浆等粗样品中的自由基含量，无需纯化。血浆和组织干草中的除草剂百草枯和敌草快已被量化为微量，但尚未见报道。为了了解还原剂对除草剂毒性的解毒作用机制，使用了维生素 E 缺乏的大鼠，但结果表明维生素 E 对百草枯中毒没有预防作用。发现在百草枯、敌草快或两者中毒的大鼠和人类中，抗坏血酸自由基水平升高。中毒血浆中的浓度迅速下降。为了深入了解百草枯对人类的毒性，我们将百草枯注射给 ODS 大鼠，因为这些大鼠与人类一样无法合成维生素 C。 ODS大鼠中毒发生时间比正常大鼠早6天。通过将维生素C的补充量改为150,300（充足水平）或3000 ppm来考察百草枯对ODS大鼠的毒性程度。过量的维生素 C 仅将中毒的发生延迟了 1 天，而正常大鼠的延迟时间要长得多。过量供应组的肺维生素C水平仅为未用百草枯处理的对照组的0.6倍。这可能是ODS大鼠比正常大鼠更早出现中毒的原因之一。

Electron spin resonance is a sensitive method which detects only unpaired electrons (radicals). By using this method radical content in crude samples such as plasma and tissue homogenates can be measured accurately without purification. The herbicides paraquat and diquat in plasma and tissues hay been quantitized in a minute amount which had not been reported yet. To understand the mechanism of antidotal action of reductants against herbicide toxicity, vitamin E deficient rats were used, but it turned out that vitamin E had no preventive effects on paraquat toxicosis.Ascorbate radical levels were found to be elevated in rats as well as humans that were intoxicated with either paraquat, diquat or both. The levels decayd quickly in the intoxicated plasma.To obtain some insight into the toxicity of paraquat in humans, it was administered to ODS rats which are unable to synthesize vitamin C,like humans. The onset of toxicosis of ODS rats was 6 days earlier than that of normal rats. The degree of toxicity of paraquat to ODS rats was examined by changing the supplementation of vitamin C as 150,300 (sufficient level) or 3000 ppm. The excess amount of vitamin C delayd the onset of toxicosis only 1 day, whereas much larger delay was observed for normal rats. The lung vitamin C level of its oversupplied group was only 0.6-fold of the control which was not treated with paraquat. This may be one of the reasons why ODS rats exhibited the toxicosis earlier than normal rats.