RESUMEN
PURPOSE: Demonstrate that the blockade of angiotensin II AT-1 receptors, through the systemic administration of olmesartan, can reduce the MCP-1 expression and the resulting macrophage accumulation in the choroid and sclera of hypercholesterolemic rabbits. METHODS: Thirty-two New Zealand rabbits were divided into 3 groups: group I (GI) was fed a standard rabbit diet; group II (GII) was fed a hypercholesterolemic diet; and group III (GIII) was fed a hypercholesterolemic diet plus olmesartan. Serum levels of total cholesterol, triglyceride, HDL cholesterol, and blood glucose were determined in fasting rabbits at the beginning of the experiment and on the day of euthanasia. The choroid and sclera were submitted to morphometric analysis as well as immunohistochemical analysis with MCP-1 and RAM-11 (macrophage marker) antibodies. RESULTS: No abnormality was detected in GI. Group II and III had significant increases in choroid-sclera complex thicknesses when compared with group I (P<0.001). GII showed a significant increase in immunoreactivity for MCP-1 in relation to GI (P=0.001) and GIII (P=0.004). GII showed a significant increase in immunoreactivity for RAM-11 of the choroid-sclera complex in relation to GI (P<0.001) and GIII (P=0.034). A significant increase in immunoreactivity for RAM-11 was observed in GIII in relation to GI (P=0.008). CONCLUSION: Olmesartan reduced the MCP-1 expression and the resultant macrophage accumulation in the choroid-sclera complex of hypercholesterolemic rabbits.