目的：分别采用摘除泪腺法和泪腺注射肉毒杆菌毒素A法诱导大鼠干眼症模型，通过对比两种干眼症模型的临床表现、病理学特点和细胞因子变化，探讨其优缺点和适用范围。

方法：健康8周龄雄性Brown Norway大鼠30只，随机分为3组：A组左眼为空白组，B组摘除大鼠左侧主泪腺，C组左侧泪腺注射肉毒杆菌毒素A。比较实验前1d，实验后3、7、14、28、42d的泪液分泌量(SⅠt)、泪膜破裂时间(BUT)、角膜荧光素钠染色评分的变化。42d观察结膜、角膜和泪腺组织病理学改变； 通过实时荧光定量PCR对白细胞介素-6(IL-6)、肿瘤坏死因子α(TNF-α)和上皮生长因子(EGF)表达量进行检测。

结果：实验后第3d开始，B、C组均出现泪液分泌量持续性减少，与A组均有差异(P<0.05)； 实验后第7d开始，B、C组均出现BUT持续性缩短以及角膜上皮染色明显增多，与A组比较有差异(P<0.05)； 以上临床数据B、C组间比较均无差异(P>0.05)。A组角膜上皮细胞形态正常，B组及C组角膜上皮均存在不同程度表层细胞丝状分离，结膜杯状细胞数目明显减少，C组泪腺组织明显萎缩。B、C组结膜和角膜组织的EGF、TNF-α和IL-6表达量均显著增高，与A组比较均有差异(P<0.05)。B、C组间EGF和TNF-α的表达均无差异(P>0.05)； 与C组比较，B组中IL-6的表达量更高(P<0.05)。

结论：摘除泪腺和泪腺注射肉毒杆菌毒素A均可以构建稳定的水液缺乏型大鼠干眼模型，建议根据实验设计及实验目的去选择合适的动物模型。

METHODS:Thirty healthy 8-week-old male Brown Norway rats were randomly assigned into three groups equally. The left eye of group A was blank group, group B was the left lacrimal gland extirpation model, the left tear gland of group C was injected with botulinum toxin A. We compared the data of Schirmer I test, tear break-up time(BUT), and the corneal fluoresceince staining scores at different times(1d before experiment, 3d, 7d, 14d, 28d, and 42d after the surgical process). We observed pathological changes of conjunctiva, cornea and lacrimal gland at 42d, and we used real-time polymerase chain reaction to analyze interleukin-6(IL-6), tumor necrosis factor-α(TNF-α)and epithelial growth factor(EGF).

RESULTS:At the 3d, compared with group A, the tear secretion of both group B and group C were continuous decrease(P<0.05). At the 7d, compared with group A, the BUT of both group B and group C began to decreased(P<0.05), and the corneal epithelial staining scores of both group B and group C began to significantly increase(P<0.05). There was no statistical difference in the above clinical data between group B and group C(P>0.05). The corneal epithelial cells in group A was set as normal morphology, while the corneal epithelial cells in group B and group C showed filamentous separation of surface cells to varying degrees, and the number of conjunctival goblet cells was decreased. The lacrimal gland of group C was obviously atrophic. In conjunctival and corneal tissues, the expression of EGF, TNF-α and IL-6 were significantly increased in group B and group C, which was statistically significant compared with group A(P<0.05). The expression of EGF and TNF-α didn't altered significantly between group B and group C(P>0.05), however, the expression of IL-6 in group B was much higher than that in group C(P<0.05).

CONCLUSION:In this study, we proved that both lacrimal gland extirpation and lacrimal gland injection botulinum toxin A could construct a stable aqueous tear deficiency dry eye rat model. The appropriate animal model should be selected according to the experimental design and research purpose.