Zinkl J G, Roberts R B, Shea P J, Lasmanis J
Arch Environ Contam Toxicol. 1981;10(2):185-92. doi: 10.1007/BF01055620.
The calculated, acute oral LD50 of acephate and methamidophos to dark-eyed juncos (Junco hyemalis) was 106 mg/kg and 8 mg/kg, respectively. Brain cholinesterase (ChE) activity in birds that died after acephate poisoning was depressed 80% below that of control birds. Birds that died of acute methamidophos poisoning had brain ChE depression of 60%. The birds killed by acephate had brain acephate residue concentrations greater than 2 mg/kg and methamidophos concentrations usually greater than 0.25 mg/kg. Eighty percent of the birds killed with methamidophos had brain methamidophos concentrations greater than 0.1 mg/kg. The five-day feeding LC50 for acephate was 1485 mg/kg. Brain ChE activities of birds which died early in the study were less depressed (51.5%) than those which died at a later date (69.6%). Brain residues of acephate and methamidophos were lower in these birds than in the birds of the acute oral LD50 studies. Brain ChE activity returned to normal within three days after the birds received a single sublethal dose of acephate. These studies indicate that the amount of acephate needed to produce the ChE depression found in other investigations in most dark-eyed juncos exposed to forest applications of insecticide is about one-fifth of the LD50; however, in a few birds the ChE activity may be depressed to near lethal levels.
乙酰甲胺磷和甲胺磷对暗眼灯草鹀（Junco hyemalis）的急性经口半数致死剂量（LD50）分别计算为106毫克/千克和8毫克/千克。乙酰甲胺磷中毒死亡的鸟类，其脑胆碱酯酶（ChE）活性比对照鸟类低80%。急性甲胺磷中毒死亡的鸟类，脑ChE活性降低了60%。死于乙酰甲胺磷的鸟类，其脑内乙酰甲胺磷残留浓度大于2毫克/千克，甲胺磷浓度通常大于0.25毫克/千克。80%死于甲胺磷的鸟类，其脑内甲胺磷浓度大于0.1毫克/千克。乙酰甲胺磷的五日喂养半数致死浓度（LC50）为1485毫克/千克。在研究早期死亡的鸟类，其脑ChE活性的抑制程度（51.5%）低于后期死亡的鸟类（69.6%）。这些鸟类脑内乙酰甲胺磷和甲胺磷的残留量低于急性经口LD50研究中的鸟类。在鸟类接受单次亚致死剂量的乙酰甲胺磷后，脑ChE活性在三天内恢复正常。这些研究表明，在大多数接触森林杀虫剂应用的暗眼灯草鹀中，产生其他调查中发现的ChE抑制所需的乙酰甲胺磷量约为LD50的五分之一；然而，在少数鸟类中，ChE活性可能会被抑制到接近致死水平。
