甲胺磷诱发母鸡迟发性神经毒性模型研究

Establishment of OPIDN hen model using methamidophos

目的:采用甲胺磷作为有机磷化合物诱导迟发性神经毒性(OPIDN)的受试物诱发母鸡OPIDN。方法:将母鸡适应性喂养1周后,随机分为实验组和对照组。分别经口和皮下给予母鸡不同剂量甲胺磷,并于给予甲胺磷前15min及给药后每隔3～6h采用阿托品和氯磷定予以保护,对照组只给予等量的溶剂和保护剂。每天观察实验动物的运动状况,按8级进行OPIDN症状分级。结果:经口途径给药导致实验动物无法进食,96h内死亡;经皮下给予甲胺磷大剂量(200～250mg/kg)导致全部母鸡死于急性中毒、中剂量多次(100～150、50、50mg/kg)可诱发少数母鸡呈现迟发性神经毒性,但症状较轻;小剂量(30mg/kg)连续15d可诱发母鸡出现不同程度的迟发性神经毒性,OPIDN发生率为31.4%。结论:30mg/kg甲胺磷连续15d经皮下给予可诱发受试母鸡出现典型OPIDN。OPIDN症状分级与剂量无相关性。

Objective: To develop an organophosphorus ester induced delayed neurotoxicity (OPIDN) hen model. Methods: The hens were randomly divided into experimental groups and control group after 7 days of acclimation. The experimental groups were administered methamidophos orally and subcutaneously respectively, with atropine and oxime against acute anticholinesterase effects of methamidophos 15min before treatment. The same doses of atropine and oxime were given every 3～6 h when needed, usually for 48h after dosing. Prophylaxis and equal solvent were also given to control hens. The clinical neurotoxic signs were observed daily, and assessed on a 0 to 8-point scale of severity. Results: All hens treated with methamidophos orally couldn't eat and died in 96h. All deaths occurred after hens were treated with 200～250 mg/kg methamidophos subscutaneously. A few hens could exhibit slight neurotoxic clinical signs of OPIDN after being treated subscutaneously with 100～150, 50 and 50mg/kg methamidophos at 1, 3, 4 days. OPIDN were induced in 31.4% of the hens when they were gotten 30mg/kg methamidophos subscutaneously daily during 15 days. Conclusion: Methamidophos (30 mg/kg) subscutaneously lasting for 15 days could develop a hen model of OPIDN. There is no correlation between the accumulated dosages of methamidophos and severity of OPIDN.