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Updated: Jun 6, 2026
Measurement of Endothelium-Dependent Vasorelaxation in the Mouse Thoracic Aorta Using Tensometric Small Volume Chamber Myography
Published on: August 12, 2022
Assessment of endothelial function of large, medium, and small vessels: a unified myograph
1Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
Insights
A novel isovolumic myograph method unifies the assessment of endothelial function across all artery sizes, from the aorta to arterioles. This technique reveals consistent arterial wall stress and tension, crucial for understanding cardiovascular diseases.
Area of Science:
- Cardiovascular Physiology
- Vascular Biology
- Biomedical Engineering
Background:
- Endothelial dysfunction is an early marker and contributor to cardiovascular diseases.
- Current methods lack a unified approach to assess endothelial function across diverse arterial sizes.
- Understanding endothelial function in vessels from aorta to arterioles is critical for cardiovascular health.
Purpose of the Study:
- To develop and validate a unified isovolumic myograph method for assessing endothelial function in a wide range of arterial sizes.
- To investigate arterial vasoreactivity and wall mechanics across different vessel dimensions.
- To establish the significance of vessel preload in maintaining endothelial function.
Main Methods:
- Utilized an isovolumic myograph to maintain constant fluid volume during vasoreactivity assessments.
- Tested arterial segments from rat aorta, femoral, mesenteric, mouse carotid, and pig coronary and carotid arteries.
- Determined endothelium-dependent vasorelaxation using vasodilators and vasoconstrictors, while controlling for vessel preload.
Main Results:
- Demonstrated a unified method for assessing arterial vasoreactivity from large to small arteries.
- Observed a consistent circumferential midstress (123–217 kPa) across vessel sizes, unlike wall tension.
- Highlighted that overinflation and axial overelongation negatively impact endothelium-dependent vasorelaxation.
Conclusions:
- The isovolumic myograph provides a standardized approach to evaluate endothelial function across the arterial tree.
- Arterial wall stress is relatively uniform, while tension varies significantly with vessel size.
- Proper vessel loading conditions are essential for accurate assessment of endothelial function and vascular reactivity.
Abstract:
Endothelial dysfunction precedes the development of morphological atherosclerotic changes and can also contribute to lesion development in cardiovascular diseases. Currently, there is a lack of a single method to determine endothelial function of the entire range of vessel dimensions from aorta to arterioles. Here we assessed endothelial function of a large range of size arteries using a unified isovolumic myograph method. The method maintains a constant volume of fluid in the lumen of the vessel during contraction and relaxation, which are characterized by an increase and a decrease of pressure, respectively. Segments of six aortas, six common femoral arteries, and six mesenteric arteries from rats; six carotid arteries from mice; and six coronary and carotid arteries from pigs were used. The endothelium-dependent dose-response vasorelaxation was determined with endothelium-dependent vasodilators while arterial preconstriction was induced with vasoconstrictors at a submaximal dose. The circumferential midtension during vascular reactivity varied from 43.1 ± 7.9 to 2.59 ± 0.46 mN/mm (from large to small arteries), whereas the circumferential midstress showed a much smaller variation from 217 ± 23.5 to 123 ± 15.3 kPa (in the same range of vessels). We also found that overinflation and axial overelongation compromised endothelium-dependent vasorelaxation to underscore the significance of vessel preload. In conclusion, an isovolumic myograph was used to unify arterial vasoreactivity from large to small arteries and shows the uniformity of wall stress and %tension throughout the range of vessel sizes.
