Morphologic study on aorta dot stained with Evans blue in normal and hypercholesterolemic rabbits.

Area of Science:

• Vascular Biology
• Atherosclerosis Research
• Histopathology

Background:

• The aortic arch and its branches are susceptible to vascular changes.
• Early detection of endothelial dysfunction is crucial for understanding atherosclerosis.
• Evans blue dye is a tool for visualizing vascular permeability.

Purpose of the Study:

• To investigate the morphological changes in the intima associated with focal permeability in normal rabbit aortas.
• To explore the relationship between these permeability changes and lipid deposition in cholesterol-fed rabbits.

Main Methods:

• Intravenous injection of Evans blue dye in normal and cholesterol-fed rabbits.
• Light and electron microscopy to examine intimal morphology and endothelial cell changes.
• Peroxidase permeability assays to assess endothelial barrier function.

Main Results:

• Focal areas of increased permeability, visualized by Evans blue, appeared rapidly in the aortic arch.
• Microscopic analysis revealed widened subendothelial space, lifted endothelial cells, and junctional dilatation.
• Cholesterol-fed rabbits exhibited punctate lipid deposition patterns similar to the focal permeability sites in normal rabbits.

Conclusions:

• Early, focal increases in aortic endothelial permeability occur in normal rabbits.
• These permeability changes share morphological similarities with early lipid deposition in experimental atherosclerosis.
• Evans blue staining highlights early vascular alterations relevant to atherogenesis.