Endothelial barrier dysfunction in diabetic conduit arteries: a novel method to quantify filtration

Area of Science:

• Vascular Biology
• Physiology
• Biophysics

Background:

• The endothelial barrier is critical in cardiovascular diseases like atherosclerosis and diabetes.
• Understanding endothelial barrier function is key to treating these conditions.
• Existing methods for assessing barrier function can be complex and less reproducible.

Purpose of the Study:

• To develop and validate an accurate, reproducible, and user-friendly method for measuring endothelial barrier function in conduit arteries.
• To quantify hydraulic conductivity (Lp) of the intact vessel wall and the endothelial barrier.
• To investigate changes in endothelial barrier function in a diabetic rat model.

Main Methods:

• An isovolumic method was employed to measure hydraulic conductivity (Lp).
• The method was validated using normal arterial segments (0.2–5.5 mm diameter).
• Femoral arteries from diabetic rats were used as pathological specimens.

Main Results:

• The isovolumic method demonstrated a linear relationship between water flux and intraluminal pressure, consistent with microvessel behavior.
• Normal arterial segments showed Lp values ranging from 3.5 to 22.1 × 10⁻⁷ cm·s⁻¹·cmH₂O⁻¹.
• The endothelial barrier of diabetic rat femoral arteries exhibited increased hydraulic conductivity (hyperpermeability), suggesting glycocalyx disruption.

Conclusions:

• The novel isovolumic method provides accurate and reproducible measurements of conduit artery endothelial barrier function.
• Diabetic rat arteries display hyperpermeability, indicating a compromised endothelial barrier.
• Disruption of the endothelial glycocalyx is the likely cause of increased permeability in diabetic conditions.