ABSTRACT
Objetivo: O objetivo deste trabalho é avaliar a expressão da molécula de adesão intercelular-1 (ICAM-1) na esclera e coroide de coelhos hipercolesterolêmicos. Métodos: Coelhos New Zealand foram organizados em dois grupos: GN (grupo dieta normal), composto por 8 coelhos (8 olhos), recebeu ração padrão para coelhos, durante 4 semanas; GH (grupo hipercolesterolêmico), composto por 13 coelhos (13 olhos), recebeu dieta rica em colesterol a 1% por 8 semanas. Foi realizada a dosagem sérica de colesterol total, triglicerídeos, HDL colesterol, glicemia de jejum no início do experimento e no momento da eutanásia. Ao final da 4ª semana para o GN e 8ª semana para o GH foi realizada a eutanásia dos animais. Os olhos foram corados com hematoxilina-eosina e submetidos à análise histológica, histomorfométrica e imunohistoquímica com o anticorpo ICAM-1. Resultados: Observou-se significativo aumento do colesterol total e triglicerídeos do GH em relação ao GN (p<0,001). A avaliação histológica com hematoxilina eosina revelou grande quantidade de macrófagos no complexo esclero-coroidal do GH. No GH constatou-se significativo aumento da espessura da esclera e coroide em relação ao GN (p<0,001). Houve significativo aumento da expressão da ICAM-1 na esclera e coroide dos animais do GH em relação ao GN (p<0,001). Conclusão: Este estudo demonstra que a dieta hipercolesterolêmica induz ao aumento da expressão da ICAM-1 na esclera e coroide de coelhos. .
Objective: The aim of this study is to investigate the expression of the intercellular adhesion molecule 1 (ICAM-1) in the sclera and choroid of hypercholesterolemic rabbits Methods: New Zealand rabbits were divided into two groups: the normal diet group (NG), with 8 rabbits (8 eyes), was fed a standard rabbit diet for 4 weeks; the hypercholesterolemic group (HG), with 13 rabbits (13 eyes), was fed a 1% cholesterol- enriched diet for 8 weeks. Total serum cholesterol, triglyceride, HDL cholesterol and fasting blood glucose exams were performed at the start of the experiment and at the euthanasia time. HG and NG animals were euthanized after 8th week and 4th week, respectively. Their eyes were stained with hematoxylin-eosin and underwent histological, histomorphometric and immunohistochemical analyses with ICAM-1 antibody. Results: The diet has induced a significant increase in total cholesterol and triglyceride levels in HG when compared with NG (p<0.001). The histological analysis with hematoxylin-eosin revealed a large number of macrophages in the HG sclera-choroid complex. Moreover, a significant increase in the HG sclera and choroid thickness was observed in relation to NG (p<0.001). There was a significant increase in the ICAM-1 expression in HG sclera and choroid in relation to NG Conclusion: This study has revealed that the hypercholesterolemic diet induces an increase in the ICAM-1 expression in the rabbits’ sclera and choroid. .
Subject(s)
Animals , Male , Sclera/metabolism , Cholesterol, Dietary , Choroid/metabolism , Intercellular Adhesion Molecule-1/metabolism , Diet, Atherogenic , Hypercholesterolemia/physiopathology , Rabbits , Retina/metabolism , Sclera/anatomy & histology , Immunohistochemistry , Retinal Neovascularization/metabolism , Cholesterol/blood , Choroid/anatomy & histology , Vascular Endothelial Growth Factor A/metabolism , Disease Models, Animal , Macrophages/metabolism , Macular Degeneration/physiopathologyABSTRACT
Purpose: This study aimed to evaluate the expression of the inflammatory cytokines TNF-α and IL-6 in the sclera and choroid of hypercholesterolemic rabbits. Method: Twenty-one New Zealand male albino rabbits were divided into two groups: NG and HG. The NG group was fed a standard rabbit diet and the HG group was fed a cholesterol-enriched diet (1%). The serum total cholesterol, triglyceride, HDL cholesterol, and fasting blood glucose levels were determined at the beginning of the experiment and on the day of euthanasia. Euthanasia of animals in the NG and HG groups was performed at the end of the 4th and 8th week, respectively. The eyes were analyzed immunohistochemically using TNF-α and IL-6 antibodies. Results: At the time of euthanasia, the HG group showed a significant increase in total cholesterol and triglyceride when compared with the NG group (p<0.001). When compared with the NG group, there was a significant increase in the expression of TNF-α (p<0.001) and IL-6 (p=0.002) in the choroid and sclera of animals in the HG group. Conclusion: This study demonstrates that the hypercholesterolemic diet induces expression of TNF-α and IL-6 in the choroid and sclera of rabbits. .
Objetivo: Avaliar a expressão das citocinas inflamatórias TNF-α e IL-6 na esclera e coroide de coelhos hipercolesterolêmicos. Método: Coelhos New Zealand foram organizados em dois grupos: GN recebeu ração padrão para coelhos; GH recebeu dieta rica em colesterol a 1%. Foi realizada a dosagem sérica de colesterol total, triglicerídeos, HDL colesterol, glicemia de jejum no início do experimento e no momento da eutanásia. Ao final da 4ª semana para o GN e 8ª semana para o GH foi realizada a eutanásia dos animais. Os olhos foram submetidos à análise imuno-histoquímica com os anticorpos TNF-α e IL-6. Resultados: O GH manifestou significativo aumento do colesterol total e triglicerídeos em relação ao GN (p<0,001). Houve significativo aumento da expressão da TNF-α (p<0,001) e da IL-6 (p=0,002) na coroide e esclera dos animais do GH em relação ao GN. Conclusão: Este estudo demonstra que a dieta hipercolesterolêmica induz ao aumento da expressão das citocinas TNF-α e IL-6 na coroide e esclera de coelhos. .
Subject(s)
Animals , Male , Rabbits , Choroid/metabolism , Hypercholesterolemia/metabolism , /metabolism , Sclera/metabolism , Tumor Necrosis Factor-alpha/metabolism , Cholesterol, Dietary , Choroid/pathology , Disease Models, Animal , Immunohistochemistry , /analysis , Macular Degeneration/metabolism , Reference Values , Sclera/pathology , Time Factors , Tumor Necrosis Factor-alpha/analysis , Vascular Endothelial Growth Factor A/analysis , Vascular Endothelial Growth Factor A/metabolismABSTRACT
OBJECTIVE: To evaluate the effect of blocking the angiotensin II AT-1 receptor by the systemic administration of candesartan on the expression of intercellular adhesion molecule-1 in the sclera and choroid of hypercholesterolemic rabbits. METHODS: New Zealand rabbits were divided into 3 groups, as follows: GI, which was fed a rabbit standard diet; GII, which was fed a hypercholesterolemic diet; and GIII, which received hypercholesterolemic diet plus candesartan. Samples of the rabbits' sclera and choroid were then studied by hematoxylin-eosin staining and histomorphometric and immunohistochemical analyses for intercellular adhesion molecule-1 expression. RESULTS: Histological analysis of hematoxylin- and eosin-stained sclera and choroid revealed that macrophages were rarely present in GI, and GII had significantly increased macrophage numbers compared to GIII. Moreover, in GII, the sclera and choroid morphometry showed a significant increase in thickness in comparison to GI and GIII. GIII presented a significant increase in thickness in relation to GI. Sclera and choroid immunohistochemical analysis for intercellular adhesion molecule-1 expression revealed a significant increase in immunoreactivity in GII in relation to GI and GIII. GIII showed a significant increase in immunoreactivity in relation to GI. CONCLUSION: Candesartan reduced the expression of intercellular adhesion molecule-1 and consequently macrophage accumulation in the sclera and choroid of hypercholesterolemic rabbits. .