Abstract
Abstract: :
Purpose: Retinal neovascularization is a major cause of vision loss. Certain cannabinoids have an anti–angiogenic effect in tumors. We describe the activity of an anti–angiogenic cannabinoid in ischemia–induced retinal neovascularization in mice. Methods: Retinal neovascularization was induced in mice pups by exposure to hyperoxia. Following return to normoxic conditions, 8 mice received daily intra–peritoneal injections of 2–arachydonoyl glycerol (2–AG) for 4 days. Control group was injected with vehicle only. Retinal neovascularization was demonstrated at post–natal day 18 (P18), the presumed peak of neovascularization. Frozen sections were stained with fluorescein Griffonia simplicifolia lectin as a marker for blood vessels and with DAPI. Preretinal endothelial cells, identified by colocalization of lectin and DAPI, were counted in central retinal sections. The results were analyzed with a chi–square statistical test. Results: All mice but one control mouse survived to P18. No apparent differences in well being or weight were noted between the experimental group and the control. The number of preretinal endothelial cells in the treated group (45.2±15) was smaller than the number of cells in the control (50.9±22.2). This difference did not reach statistical significance (p=0.07). Conclusions: 2–AG treated mice showed a trend toward decreased oxygen–induced neovascularization. Additional experiments with other cannabinoids, which have a more potent anti–angiogenic activity are indicated.
Keywords: retinal neovascularization • retinopathy of prematurity • pharmacology