Agarwal D K, Misra D, Agarwal S, Seth P K, Kohli J D
J Toxicol Environ Health. 1982 Mar;9(3):451-9. doi: 10.1080/15287398209530177.
Administration of parathion resulted in a greater inhibition of acetylcholinesterase (AChE) activity of plasma, erythrocytes, and brain in female rats than in male rats. No sex-related difference was observed in the antiacetylcholinesterase activity of paraoxon, an active metabolite of parathion. Gonadectomy increased the susceptibility of males but had no perceptible effect on females, resulting in comparable inhibition of AChE by parathion in both sexes. Administration of testosterone led to recovery from increased sensitivity to the antiacetylcholinesterase activity of parathion in castrated males and afforded partial protection to ovariectomized females. On the other hand, administration of estradiol further enhanced the enzyme inhibition by parathion in castrated males but had no significant effect on that in ovariectomized females. Alterations in the status of sex hormones did not affect the antiacetylcholinesterase activity of paraoxon in plasma and erythrocytes. However, inhibition of AChE activity by paraoxon was significantly higher in brains of gonadectomized rats than those of normal rats and the effect was reversible on administration of the respective sex hormones. The results indicate that testosterone plays an important role in determining parathion toxicity (as reflected by its antiacetylcholinesterase activity), probably by activating the oxidative cleavage of the insecticide into nontoxic metabolites.
对雌性大鼠施用对硫磷后，其血浆、红细胞和脑内乙酰胆碱酯酶（AChE）活性的抑制程度大于雄性大鼠。对硫磷的活性代谢产物对氧磷的抗乙酰胆碱酯酶活性未观察到性别相关差异。去势增加了雄性大鼠的易感性，但对雌性大鼠没有明显影响，导致对硫磷对两性AChE的抑制作用相当。给去势雄性大鼠施用睾酮可使其对硫磷抗乙酰胆碱酯酶活性的敏感性增加得到恢复，并为去卵巢雌性大鼠提供部分保护。另一方面，给去势雄性大鼠施用雌二醇会进一步增强对硫磷对酶的抑制作用，但对去卵巢雌性大鼠没有显著影响。性激素状态的改变不影响血浆和红细胞中对氧磷的抗乙酰胆碱酯酶活性。然而，去势大鼠脑内对氧磷对AChE活性的抑制作用明显高于正常大鼠，且施用相应性激素后这种作用是可逆的。结果表明，睾酮在决定对硫磷毒性（以其抗乙酰胆碱酯酶活性为反映）方面起重要作用，可能是通过激活杀虫剂的氧化裂解为无毒代谢产物来实现的。
