VEGF and NGF are known to modulate corneal healing, neovascularisation and tear secretion. While a VEGF-NGF cross talk has been recently shown to modulate corneal healing in rats, it is not known whether it also plays a role in the regulation of lacrimal function. In this study we aim to investigate the effects of anti-VEGF eye drop treatment on lacrimal gland function and on the local expression of VEGF and NGF in rats. Tear function was measured in 3 months old rats by modified Schirmer test at baseline and after 3 weeks of topical anti-VEGF eye drop treatment. Whole lacrimal glands from rats were removed after treatment and analysed by ELISA for VEGF and NGF levels. To investigate if the effects of anti-VEGF were mediated by changes in the NGF-pathway, we repeated the experiments in RCS rats, a strain with NGF-pathway impairment associated with decreased tear flow. After topical treatment with anti-VEGF eye drops, an increase in tear secretion was observed in both wild-type and RCS rats. A significant decrease of VEGF levels was also observed in lacrimal glands of both RCS and SD rats, accompanied by a significant increase in NGF levels. Inhibition of VEGF at the ocular surface in rats results in changes of tear function and lacrimal gland levels of VEGF and NGF. Further studies on the VEGF/NGF cross-talk at the ocular surface may expand our knowledge on the pathogenesis of several diseases characterized by tear dysfunction.

中文翻译：

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贝伐单抗滴眼液治疗通过改变VEGF和NGF泪腺水平刺激大鼠的泪液分泌。

已知VEGF和NGF可调节角膜愈合，新血管形成和泪液分泌。尽管最近已经显示出VEGF-NGF串扰可调节大鼠角膜的愈合，但尚不清楚它是否在调节泪功能中也起作用。在这项研究中，我们旨在研究抗VEGF眼药水治疗对泪腺功能以及大鼠VEGF和NGF局部表达的影响。在基线和局部抗VEGF眼药水治疗3周后，通过改良的Schirmer试验在3个月大的大鼠中测量泪液功能。处理后将大鼠的整个泪腺切除，并通过ELISA分析其VEGF和NGF水平。为了研究抗VEGF的作用是否由NGF途径的变化介导，我们在RCS大鼠中重复了该实验，具有与泪液流量减少相关的NGF途径受损的菌株。用抗VEGF眼药水局部治疗后，在野生型和RCS大鼠中均观察到泪液分泌增加。在RCS和SD大鼠的泪腺中也观察到VEGF水平的显着降低，同时NGF水平也显着升高。大鼠眼表皮生长因子的抑制导致泪液功能和泪腺中VEGF和NGF水平的变化。眼表皮VEGF / NGF串扰的进一步研究可能会扩展我们对几种以泪液功能障碍为特征的疾病的发病机理的认识。在RCS和SD大鼠的泪腺中也观察到VEGF水平的显着降低，同时NGF水平也显着升高。大鼠眼表皮生长因子的抑制导致泪液功能和泪腺中VEGF和NGF水平的变化。眼表皮VEGF / NGF串扰的进一步研究可能会扩展我们对几种以泪液功能障碍为特征的疾病的发病机理的认识。在RCS和SD大鼠的泪腺中也观察到VEGF水平的显着降低，同时NGF水平也显着升高。大鼠眼表皮生长因子的抑制导致泪液功能和泪腺中VEGF和NGF水平的变化。对眼表皮VEGF / NGF串扰的进一步研究可能会扩展我们对几种以泪液功能障碍为特征的疾病的发病机理的认识。