Avaliação ultra-estrutural dos vasos da íris, corpo ciliar e retina em ratos diabéticos aloxânicos
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Data
2008-02-27
Autores
Almeida, Carla Albertina Martins [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo do estudo foi avaliar a influência do diabetes sobre os vasos da íris, corpo ciliar e retina. Para isto, foi realizado estudo experimental, utilizando 20 ratos da raça Wistar, divididos em dois grupos: Grupo Controle (GC) e Grupo Diabético (GD). A indução do diabetes foi feita por injeção de aloxana, 42 mg/Kg de peso. Os animais foram observados em 3 momentos experimentais: M1-15 dias após a indução do diabetes, M2 -1 mês após M1 e M3 -12 meses após M1. Foram considerados para o estudo os animais do GD que em M1 apresentavam diabetes grave. Realizou-se acompanhamento diário de parâmetros clínicos (peso, diurese, ingestão hídrica e ingestão alimentar) e avaliação mensal de glicemia e glicose urinária. Nos momentos experimentais M2 e M3 foram realizadas enucleação e preparo dos olhos para avaliação sob microscopia eletrônica de transmissão. Os resultados obtidos mostraram que os animais diabéticos tiveram importante redução de peso, aumento de ingestão hídrica, aumento de ingestão alimentar e aumento de diurese, em relação aos animais controle. Na avaliação morfológica os três grupos de vasos tiveram alterações similares, com espessamento da membrana basal nas células endoteliais e pericitos, maior número de corpos densos, lisossomos, vesículas, vacúolos e figuras de mielina, que estavam presentes em GCM2 e foram mais acentuadas nos grupos diabéticos. Não foram observados microaneurismas na parede vascular. A análise morfométrica mostrou aumento significativo na espessura da membrana basal de vasos irianos nos animais diabéticos. Concluí-se que os vasos da íris, corpo ciliar e retina sofrem a influência do estado diabético. As alterações são progressivas, afetando tanto as células endoteliais, como as pericíticas.
The purpose of this study was to evaluate the influence of diabetes on vessels of iris, ciliary’s body and retina. For this, prospective experiment was accomplished, using 20 Wistar rats, divided in two groups: Control Group (CG) and Diabetic Group (DG). The diabetes induction was made by aloxana injection, 42 mg/Kg of weight. The animals had been observed at 3 experimental moments: M1-15 days after the diabetes induction, M2 - 1 month M1 and M3 -12 months after M1. They were considered for the study the animals of the DG that presented serious diabetes in M1. Clinical parameters had daily been followed (weight, diuresis, water ingestion and alimentary ingestion) and monthly evaluation of glycemia and urinary glucose. At the experimental moments M2 and M3 it was realized enucleation and preparation of the eyes for optic microscopy and electronic transmission microscopy evaluation. The gotten results had shown that the diabetic animals had had important weight reduction, water ingestion increase, alimentary ingestion increase and diuresis increase, compared to the animals of the CG. In the morphologic evaluation it has been observed that the three groups of vessels have had similar alterations, with thickening of the basal membrane in the endothelial cells and pericytes, greater number of dense bodies, lysosomes, vesicles, vacuoles and myelin figures” that they were in GCM2 and had been accentuated in diabetic groups. Microaneurysms in the vascular wall had not been observed. The morphometric analysis showed significant increase in the thickness of the basal membrane of iris vessels in diabetic animals. We conclude that iris, ciliary’s body and retina vessels suffer the influence from the diabetic state. The alterations are gradual, affecting in such a way the endothelial cells, as the pericytes.
The purpose of this study was to evaluate the influence of diabetes on vessels of iris, ciliary’s body and retina. For this, prospective experiment was accomplished, using 20 Wistar rats, divided in two groups: Control Group (CG) and Diabetic Group (DG). The diabetes induction was made by aloxana injection, 42 mg/Kg of weight. The animals had been observed at 3 experimental moments: M1-15 days after the diabetes induction, M2 - 1 month M1 and M3 -12 months after M1. They were considered for the study the animals of the DG that presented serious diabetes in M1. Clinical parameters had daily been followed (weight, diuresis, water ingestion and alimentary ingestion) and monthly evaluation of glycemia and urinary glucose. At the experimental moments M2 and M3 it was realized enucleation and preparation of the eyes for optic microscopy and electronic transmission microscopy evaluation. The gotten results had shown that the diabetic animals had had important weight reduction, water ingestion increase, alimentary ingestion increase and diuresis increase, compared to the animals of the CG. In the morphologic evaluation it has been observed that the three groups of vessels have had similar alterations, with thickening of the basal membrane in the endothelial cells and pericytes, greater number of dense bodies, lysosomes, vesicles, vacuoles and myelin figures” that they were in GCM2 and had been accentuated in diabetic groups. Microaneurysms in the vascular wall had not been observed. The morphometric analysis showed significant increase in the thickness of the basal membrane of iris vessels in diabetic animals. We conclude that iris, ciliary’s body and retina vessels suffer the influence from the diabetic state. The alterations are gradual, affecting in such a way the endothelial cells, as the pericytes.
Descrição
Palavras-chave
Diabetes, Iris (Olhos), Retina - Vaso sanguíneos, Diabetes - Vessels of iris
Como citar
ALMEIDA, Carla Albertina Martins. Avaliação ultra-estrutural dos vasos da íris, corpo ciliar e retina em ratos diabéticos aloxânicos. 2008. 115 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, 2008.