新型光敏剂酞菁锌在兔眼组织分布的研究

Localization of a new hydrophilic photosensitizer:Zinc phthalocyanine in the rabbit eye

目的探讨新型光敏剂酞菁锌在色素兔脉络膜和视网膜分布情况及其浓度的高峰期,为用金属酞菁介导的光动力疗法(PDT)提供相关的参考方案。设计实验研究。研究对象健康有色家兔28只。方法6只兔静脉注射不同剂量酞菁锌药后进行眼底血管造影观察。对照组(2只)经耳缘静脉注入等量生理盐水,实验组(20只)经耳缘静脉注入酞菁锌20mg/kg,在给药后5、10、15、30和60min摘除眼球作冰冻切片(每组8眼),荧光显微镜下观察眼球的荧光分布。主要指标眼底血管造影荧光充盈情况及冰冻切片荧光程度。结果注射20mg/kg酞菁锌后10～20s,荧光造影显示脉络膜渐呈弥漫高荧光,随时间推移荧光强度逐渐减弱。荧光显微镜下观察给药后10～20min为酞菁锌在眼组织分布的高峰期,30min后药物荧光有所下降,视网膜层仍有少量荧光,60min药物荧光基本已消退。结论酞菁锌主要迅速分布于脉络膜和视网膜色素上皮层,而其他组织如内层视网膜、巩膜等药物荧光分布少。提示酞菁锌介导的PDT治疗脉络膜新生血管最佳时间是给药后10～20min进行光照。

Objective To investigate the intraocular localization of zinc phthalocyanine photosensitizer by using fluorescence microscopy and digital fundus fluorescence angiography. Design Experimental study. Participants 28 normal pigment rabbits. Methods Digital fundus angiography with zinc phthalocyanine （10, 20, 30mg/kg） was performed in 6 rabbits. 0.9% salt solution was intravenously administered in the control group （n=2） and zinc phthalocyanine （20mg/kg） was intravenously administered in the experiment group （n= 20）. The eyes were enucleated and examined with fluorescence microscopy at 5, 10, 15, 30 and 60 minutes after injection. Main Outcome Measures Fundus angiography and fluorescence microscopy. Results Fluorescence from the choroid and retinal pigment epithelium was increased 10-20s after zinc phthalocyanine （20mg/kg） administered. Examined with fluorescence microscopy,crest-time is 10-20 minutes after dye injection. 30 minutes later, mild fluorescence detected from the retina, fluorescence almost fade away at 60 minutes. Conclusion Zinc phthalocyanine accumulate rapidly in the choroid and retinal pigment epithelium and less rapidly in the outer retina. Differences in ocular localization of the photosensitizer are demonstrated. Zinc phthalocyanine-mediated photodynamic therapy CNV optimal timing of laser irradiation after dye administration is 10-20 minutes.