The Effects Of Octreotide On Retinal Neovascularization In Mouse

Objectives To observe retinal neovascularization and explore the effects of octreotide on retinal neovascularization, the mouse models with retinopathy were set up under the hypoxia condition, and octreotide was intravitreally injected in mice with neovascularization.Methods 36 one-week old Kunming mice were selected and divided into 3 groups at random: normal control group (n=8),control group with high oxygen exposure(n=8) and group injected with octreotide (n=20).The mouse models with retinopathy were established .The right eyes of mice in octreotide group received an intravitreal injection of 1 μl of octreotide and the same volume of BSS was injected into the left eyes of octreotide group mice as a control. 4 mice (2 twelve-days old mice and 2 seventeen-days old mice) were selected randomly from each group, and retinal flatmount was used to observed the changes of retinal vessels. The inhibitory effects of octreotide on retinal neovascularization were evaluated by counting the endotheliocyte nuclei of new vessels extending from retina to vitreous in the tissue-slice of the rest seventeen-days mice. Immunohistochemical method was used to identify the cells extending from retina to vitreous. All retinal layers were observed under microscope.Results Constriction and occlusion of the retinal blood vessels and decrease in perfusion were found under the hyperoxia condition, and dilation and proliferation of blood vessels were found under the relatively hypoxia status. Regular distribution and reduced density of the rtinal blood vessels in the treatment eyes of octreotide group were found in retinal flatmount. The number of the endotheliocyte nuclei of new vessels extending from retina to vitreous was more in the eyes in hyperoxia group than normal control group (p<0.05). Compared with the eyes in hyperoxia group and theleft eyes (injected with BSS) of octreotide group, the nuclei of new blood vessels in the right eyes(injected with octreotide) were less significantly (p<0.05). There were no significant difference in the number of the nuclei between the hyperoxia group and the left eyes (injected with BSS) of octreotide group (p>0.05). Immunohistochemical staining for factor CD31 proved the endotheliocyte to be from vessels. No histologic evidence of retinal toxicity or inflammatory response was found in the tissue-slice after injection of octreotide.Conclusion Retinal neovascularization can be inhibited by intravitreal injection of octreotide, which suggests that intravitreal injection of octreotide may have potential therapeutic benefits in retinal vascular disease.