Higgins R D, Yu K, Sanders R J, Nandgaonkar B N, Rotschild T, Rifkin D B
Department of Pediatrics, Georgetown University Medical Center, Washington, DC 20007, USA.
Curr Eye Res. 1999 Jan;18(1):20-7. doi: 10.1076/ceyr.18.1.20.5390.
To assess the effect of diltiazem, a calcium channel blocking agent, on oxygen induced retinopathy (OIR) in a mouse model using neovascular nuclei quantitation and a quantitative scoring system based on examining fluorescein perfused retinal whole mount preparations.
The mouse model of oxygen induced retinopathy consisting of a 5 day exposure to 75% oxygen from postnatal day 7 to 12 was used to produce retinal neovascularization. Fluorescein conjugated dextran angiography of retinal vasculature was performed and retinal whole mounts were prepared to score features of retinopathy. The parameters that were scored in a masked fashion included blood vessel growth, blood vessel tuft formation, extra retinal neovascularization, degree of central vasoconstriction, retinal hemorrhage, and tortuosity of vessels. Diltiazem (0.05-0.5 mg/kg/day subcutaneously for five days) was administered to mice pups during exposure to oxygen to determine if calcium channel blockade altered retinopathy. In addition, quantification of retinal neovascular nuclei was performed in a masked fashion with periodic acid Schiff (PAS) staining of frozen eye sections.
Animals that were exposed to hyperoxia for five days had a median (25th, 75th quartile) retinopathy score of 9 (8,11) versus control animals that had a retinopathy score of 1 (0,1) with p<0.001. Subscores for blood vessel growth, blood vessel tufts, extra-retinal neovascularization, central vasoconstriction, hemorrhage, and blood vessel tortuosity were all significantly different between control and treated animals. In addition, quantification of neovascular nuclei showed a significant increase in the number of nuclei extending beyond the inner limiting membrane into the vitreous in hyperoxic treated animals. Diltiazem at doses of 0.2 and 0.5 mg/kg/day improved the retinopathy as measured by the total retinopathy score [5 (4,6) and 4 (3.75,5.25), respectively]. The average number of extraretinal neovascular nuclei per retinal section (mean +/-standard deviation) was significantly decreased by diltiazem at doses of 0.2 and 0.5 mg/kg/day (31.4+/-18.8 and 20.9+/-6.9, respectively) when compared to hyperoxic treated animals (56.1+/-21.5).
Diltiazem reduces oxygen induced retinopathy in the mouse as measured by a scoring system based on a retinal whole mount method of retinal neovascularization and by quantification of extra retinal neovascular nuclei.
使用新生血管核定量以及基于对荧光素灌注视网膜全层标本检查的定量评分系统，评估钙通道阻滞剂地尔硫䓬对小鼠氧诱导性视网膜病变（OIR）的影响。
采用从出生后第7天至12天暴露于75%氧气5天的氧诱导性视网膜病变小鼠模型来诱导视网膜新生血管形成。对视网膜血管进行荧光素偶联葡聚糖血管造影，并制备视网膜全层标本以对视网膜病变特征进行评分。以盲法评分的参数包括血管生长、血管襻形成、视网膜外新生血管形成、中央血管收缩程度、视网膜出血以及血管迂曲度。在小鼠暴露于氧气期间给予地尔硫䓬（0.05 - 0.5毫克/千克/天，皮下注射5天），以确定钙通道阻滞是否会改变视网膜病变。此外，对冷冻眼切片进行过碘酸希夫（PAS）染色，以盲法对视网膜新生血管核进行定量。
暴露于高氧环境5天的动物视网膜病变评分中位数（第25、75四分位数）为9（8,11），而对照动物的视网膜病变评分为1（0,1），p<0.001。对照动物与治疗动物在血管生长、血管襻、视网膜外新生血管形成、中央血管收缩、出血以及血管迂曲度的子评分上均存在显著差异。此外，新生血管核定量显示，在高氧治疗的动物中，延伸至内界膜之外进入玻璃体的核数量显著增加。以总视网膜病变评分衡量，0.2毫克/千克/天和0.5毫克/千克/天剂量的地尔硫䓬改善了视网膜病变[分别为5（4,6）和4（3.75,5.25）]。与高氧治疗的动物（56.1±21.5）相比，0.2毫克/千克/天和0.5毫克/千克/天剂量的地尔硫䓬使每个视网膜切片的视网膜外新生血管核平均数量（均值±标准差）显著减少（分别为31.4±18.8和20.9±6.9）。
通过基于视网膜全层新生血管形成方法的评分系统以及对视网膜外新生血管核的定量测定，地尔硫䓬可减轻小鼠的氧诱导性视网膜病变。
