摘要
目的探讨百草枯致[损伤的病理]变,为构建相应动物模型奠定基础。方法将20只普通级健康成年白色新西兰家兔按照随机数字表法分为5组,每组4只。每只家兔左眼结膜囊内滴入百草枯原液100μl后立即将其眼睑轻轻闭合,使药液分别保留30 s(30 s组)、1 h(1 h组)、4 h(4 h组)、8 h(8 h组)和24 h(24 h组);右眼结膜囊内滴入生理盐水100μl作为对照。接触百草枯原液达规定时间后,以生理盐水分别冲洗双眼5 min。应用裂隙灯和角膜荧光素染色技术观察眼结膜、虹膜和角膜的损伤情况并进行评分,记录眼损伤累加最高积分和损伤完全恢复时间。实验第21天处死动物,取角膜组织进行组织病理学观察。结果 30 s组家兔出现轻至中度结膜刺激症状,未见角膜、虹膜损伤,实验第2天眼损伤累加最高积分达峰,为(14.0±2.3)分,眼损伤完全恢复时间为(9.5±0.6)d,角膜组织切片未见明显病理改变。1 h组家兔出现中至重度结膜刺激症状,虹膜无损伤,角膜有局灶性损伤,染毒后(5.5±1.9)d眼损伤累加最高积分达峰,为(47.5±8.5)分,高于30 s组(P<0.05),眼损伤完全恢复时间为(13.5±2.4)d,组织切片见角膜受损部位上皮扁平细胞层缺失。4 h组、8 h组和24 h组家兔除了出现重度结膜刺激症状外,均出现角膜和虹膜损伤,损伤程度随着接触百草枯原液时间的延长而加重,眼损伤累加最高积分分别在染毒后(6.2±1.0)、(7.7±1.0)和(7.2±2.1)d达峰,分别为(67.5±10.5)、(79.5±9.7)和(80.0±9.5)分,均高于30 s组和1 h组(均P<0.05),3组之间差异无统计学意义(P>0.05)。4 h组中有2只家兔分别在实验第12、19天眼损伤完全恢复,另2只和8 h组、24 h组的全部家兔至实验第21天眼损伤未完全恢复。组织病理学观察显示4 h组家兔角膜上皮细胞部分脱落,呈虫蚀样改变;8 h组角膜上皮扁平细胞和棘状细胞脱落,仅存柱状基底细胞,部分深达角膜基质层,角膜基质纤维板层结构紊乱,可见肉芽组织和角膜新生血管;24 h组角膜上皮完全剥脱,仅存基质层、内弹力层和内皮细胞层。结论眼接触百草枯原液30 s即可导致结膜损伤,接触1 h可致角膜损伤,接触时间≥4 h可造成角膜混浊、角膜损伤瘢痕愈合等难以恢复的眼损伤。家兔眼接触百草枯原液≥4 h出现的眼损伤可作为百草枯致眼损伤的动物模型。
Objective To study the pathological changes of paraquat-induced ocular injury process in rabbits in order to lay the basis for creating an animal model of paraquat-induced ocular injury. Methods Using a random number table, 20 healthy conventional New Zealand white rabbits were divided into 5 groups, each group comprised 4 rabbits, paraquat stock solution 100 I^1 was dropped into left conjunetival sac of each rabbit and then its eyelids were closed, paraquat stock solution was kept in conjunctival sar for 30 seconds （ the 30 seconds group）, 1 hour （ the 1 hour group）, 4 hours （ the 4 hours group）, 8 hours （ the 8 hours group）, and 24 hours （ the 24 hours group）, respectively. The normal saline solution 100 l was dropped into the right conjunctival sac of each rabbit served as controls. After exposure to paraquat stock solution, both eyes were washed with normal saline solution for 5 minutes. Conjunctival, iridal, and corneal injuries were observed under slit lamp and corneal fluorescent staining and scores were recorded. The highest accumulated score of ocular injury and complete recovery time were recorded. The animals were sacrificed on day 21 of experiment and the corneas were detached for histopathological observation. Results In the 30 seconds group, mild to moderate conjunctival irritation occurred and iridal and corneal injuries were not observed ; the highest accumulated score of ocular injury reached a peak of （14.0± 2.3） on day 2 of experiment; the complete recovery time was （9.5 ± 0.6 ） days; corneal tissue slice revealed no marked pathologic changes. In the 1 hour group, moderate to severe conjunctival irritation appeared, iris did not develop injury and cornea presented with local injure; （5.5 ± 1.9） days after exposure to paraquat stock solution, the highest accumulated score of ocular injury reached a peak of （47.5 ±8.5） which was higher than that in the 30 seconds group （P 〈0.05） ; the complete recovery time was （13.5±2.4） days; tissue slice showed epithelium flat cell layer losing at corneal injury site. In the 4 hours, 8 hours, and 24 hours groups, the rabbits developed corneal and iris injury which gradually aggravated with the prolonged exposure to paraquat stock solution besides severe conjunctival irritation; on days （6.2 ± 1.0）, （ 7.7 ±1.0）, and （7.2 ± 2.1 ） of experiment, the highest accumulated score of ocular injury reached the peak of （67.5 ± 10.5）, （79.5 ± 9.7）, and （80.0 ± 9.5 ）, respectively, which were all higher than the scores in the 30 seconds and 1 hour groups （all P 〈 0.05）. There was no statistically significant difference among the 4 hours, 8 hours, and 24 hours groups （P 〉0.05）. Two rabbits in the 4 hours group recovered completely on days 12 and 19 of experiment, respectively, while the other 2 rabbits and all rabbits in the 8 hours and 24 hours groups did not recover completely until 21 days of experiment. Histopathological observation revealed the following： in the 4 hours group, a part of corneal epithelium cells of rabbits losing and ＂moth-eaten＂ changes; in the 8 hours group, corneal epithelium flat cells and prickle cells losing, columnar basal cells existing and a part of them even reaching corneal stroma layer, structural disorder of corneal stroma fiberboard layer, granulation tissue and corneal neovascularization appearing; in the 24 hours group, whole corneal epithelial layer exfoliating and only stroma layer, intraelastic layer, and endothelial cell layer existing. Conclusion Exposure to paraquat stock solution for 30 seconds could cause conjunctival injury and exposure to paraquat stock solution for 1 hour could cause corneal injury. Exposure to paraquat stock solution for more than 4 hours could cause ocular injury, which was difficult to recover, such as nubecula and scar healing of corneal injury. Ocular injury following rabbit eye was exposed to paraquat stock solution for ≥ 4 hours might serve as an animal mode of ocular injury to paraquat.
出处
《药物不良反应杂志》
2012年第2期82-87,共6页
Adverse Drug Reactions Journal
基金
国家科技支撑计划(2006BAI06B01-01)
中国疾病预防控制中心职业卫生与中毒控制所青年科技基金项目(11ZD0504)
关键词
百草枯
眼损伤
角膜
paraquat
ocular injury
cornea
