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 investigate the changes of paraquat-induced pathological changes and lay the foundation for the establishment of animal models. Methods Twenty normal healthy white New Zealand white rabbits were divided into 5 groups according to the random number table method, 4 in each group. Each rabbits were injected with paraquat solution 100μl into the conjunctival sac of the left eye and the eyelids of the rabbits were closed gently for 30 s (30 s), 1 h (1 h), 4 h Group), 8 h (8 h group) and 24 h (24 h group). 100 μl normal saline was injected into the right conjunctival sac as a control. After contact with the paraquat solution for a specified period of time, wash both eyes with saline for 5 min. Slit lamp and corneal fluorescein staining techniques were used to observe and score the conjunctiva, iris and corneal injury. The highest integral of eye damage and the complete recovery time of injury were recorded. Animals were sacrificed on the 21st day and corneal tissue was taken for histopathological observation. Results There was no corneal and iris injury in the 30 s rabbits. The highest integral of the eye injury peaked at 14.0 ± 2.3 on the second day of the experiment, and the complete recovery time of the ocular injury was 9.5 ± 0.6) d, corneal tissue sections showed no significant pathological changes. The rabbits in 1 h group showed moderate to severe conjunctival irritation with no damage to the iris and focal corneal injury. The highest accumulated peak value of eye injury after (5.5 ± 1.9) d exposure was (47.5 ± 8.5) points and high At 30 s (P <0.05), the complete recovery time of eye injury was (13.5 ± 2.4) d, and the absence of epithelial flat cell layer in corneal damaged area was observed in tissue sections. In addition to the symptoms of severe conjunctival irritation, rabbits in 4 h group, 8 h group and 24 h group showed corneal and iris injury. The injury degree aggravated with prolonged exposure to paraquat solution, (6.2 ± 1.0), (7.7 ± 1.0) and (7.2 ± 2.1) d respectively, which were significantly higher than that of the control group (67.5 ± 10.5, 79.5 ± 9.7 and 80.0 ± 9.5, And 1 h group (all P <0.05). There was no significant difference between the three groups (P> 0.05). In the 4 h group, 2 rabbits were completely recovered on the 12th and 19th day, respectively, while the other 2 rabbits in the 8th and 24th hour groups did not fully recover to the 21st day. Histopathological examination showed that the corneal epithelial cells in the 4 h group were partly exfoliated and changed into worm-eaten samples. After 8 h, corneal epithelial flat cells and spinous cells shed, only the columnar basal cells, part of the deep corneal stroma, corneal stroma The structure of the fibrous layer was disorganized, showing granulation tissue and corneal neovascularization. The corneal epithelium was completely exfoliated in 24 h group, only the stromal layer, the internal elastic layer and the endothelial cell layer were found. Conclusion Eye contact with paraquat solution for 30 s can lead to conjunctival injury. Exposure to paraquat can cause corneal injury at 1 h, and contact time ≥ 4 h can cause corneal opacity and corneal scar healing. Eye damage caused by paraquat liquid in rabbits for 4 hours can be used as an animal model of paraquat-induced eye damage.