Evaluating Vascular Hyperpermeability-inducing Agents in the Skin with the Miles Assay

Area of Science:

• Physiology
• Pathology
• Pharmacology

Background:

• The vascular endothelium acts as a critical barrier, regulating the passage of substances between blood and tissues.
• Dysregulation of endothelial barrier function, often due to prolonged exposure to cytokines and growth factors, can lead to chronic vascular hyperpermeability and edema.
• The Miles assay is an established in vivo method to assess vascular leakage, serving as a proxy for hyperpermeability.

Purpose of the Study:

• To provide a detailed protocol for performing the Miles assay in mice.
• To enable the study of vascular hyperpermeability and its underlying molecular mechanisms.
• To facilitate the identification of agents or targets that modulate vascular permeability.

Main Methods:

• Intravenous injection of Evans blue dye to label circulating albumin.
• Intradermal injections of permeability-inducing agents and vehicle controls into opposing flanks of mice.
• Quantification of extravasated Evans blue dye in the dermis to measure vascular leakage.

Main Results:

• The Miles assay allows for the quantitative assessment of vascular leakage induced by various agents.
• The procedure can be adapted for use in both wild-type and genetically modified mouse models.
• The assay can be combined with drug administration to investigate the effects of pharmacological interventions on vascular permeability.

Conclusions:

• The Miles assay is a valuable tool for studying vascular hyperpermeability in vivo.
• This protocol provides a standardized method for researchers using mouse models.
• The assay aids in understanding the molecular mechanisms of vascular permeability and in discovering new therapeutic strategies.