Analysis of poisons by using electron spin resonance method

电子自旋共振是一种敏感的方法，只检测未配对的电子(自由基)。该方法无需纯化，即可准确测定血浆和组织匀浆等粗品中的自由基含量。血浆和组织中的除草剂百草枯和敌草枯已被立即定量，数量尚未见报道。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。研究发现，无论是百草枯、敌草枯或两者都能提高大鼠和人的抗坏血酸自由基水平。在中毒的血浆中，百草枯的水平迅速下降。为了了解百草枯对人类的毒性，它被用在无法合成维生素C的消耗臭氧层物质大鼠身上，就像人类一样。与正常大鼠相比，ODS大鼠中毒发病时间提前6d。通过改变维生素C的补充量为150、300(足够量)或3000ppm来检测百草枯对消耗臭氧层物质大鼠的毒性程度。过量维生素C只使中毒的发生延迟了1天，而正常大鼠的延迟时间要长得多。其过量供给组的肺维生素C水平仅为未用百草枯的对照组的0.6倍。这可能是消耗臭氧层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.