Dextrans and glycogens as particulate tracers for studying capillary permeability

Area of Science:

• Biomedical research
• Vascular biology
• Pharmacology

Background:

• Capillary permeability is crucial for understanding physiological and pathological processes.
• Particulate tracers are valuable tools for investigating the integrity of the blood-brain barrier and other microvascular systems.
• Existing tracers may have limitations in terms of biocompatibility, detection, or size range.

Purpose of the Study:

• To evaluate the suitability of commercially available glycogens and dextrans as biological particulate tracers.
• To assess the biocompatibility and vascular effects of these polysaccharides.
• To determine their utility in studying both large and small pore systems in capillaries.

Main Methods:

• Intravenous injection and topical application (cremaster test) in mice and Wistar-Furth rats.
• Assessment of vascular leakage following tracer administration.
• Electron microscopy with lead staining after aldehyde-OsO(4) fixation in phosphate buffer.

Main Results:

• Glycogens and dextrans were well tolerated upon intravenous injection.
• No significant vascular leakage was observed with topical application in the cremaster test.
• Particles were adequately visualized using lead staining after fixation, covering a size range of approximately 45 Å to 300 Å.

Conclusions:

• Commercially available glycogens and dextrans are suitable and safe biological particulate tracers.
• These tracers can be effectively used to investigate capillary permeability in both large and small pore systems.
• The findings support the use of these polysaccharides in microcirculation research.