Assessment of endothelial function of large, medium, and small vessels: a unified myograph

Abstract

Lu X, Kassab GS. Assessment of endothelial function of large, medium, and small vessels: a unified myograph. Am J Physiol Heart Circ Physiol 300: H94 -H100, 2011. First published November 12, 2010; doi:10.1152/ajpheart.00708.2010.-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 Ϯ 7.9 to 2.59 Ϯ 0.46 mN/mm (from large to small arteries), whereas the circumferential midstress showed a much smaller variation from 217 Ϯ 23.5 to 123 Ϯ 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. isovolumic myograph; wire myograph; pressure myograph VASCULAR ENDOTHELIAL DYSFUNCTION is widely considered to be a consequence, a biomarker, and a mediator of the adverse effects of cardiovascular risk factors (2,4,5,11,15,18,21). Endothelial dysfunction precedes the development of morphological atherosclerotic changes and can also contribute to lesion development and later clinical complications (15,23,24). Endothelial dysfunction has also been shown to be a predictor of adverse outcomes in patients with coronary artery disease (10,11,20). Although endothelial dysfunction may be indicated by several biomarkers such as the expression of endothelial nitric oxide (NO) synthase, the expression of cyclooxygenase, and the production of nitric oxide or prostacyclin, the vasodilation of blood vessel in response to endothelium-dependent agonists is the gold standard.The wire and pressure myographs have been used extensively to study the vasoreactivity and pharmacology of large and small vessels, respectively (7-9, 12-16, 19, 26). The applicability of wire myograph is in vessels with a diameter range from large vessels (aorta) down to about 500 m. The attachment of vessel rings to hooks, however, ca...

Biaxial vasoactivity of porcine coronary artery

“…The heart was harvested and placed in an ice-cold saline bath. A fresh right coronary artery (RCA) of ϳ2.5 cm was dissected free of fat and connective tissue, and the branches were ligated with suture under dissection microscope in 4°C HEPES PSS (physiological saline solution) (16,17).…”

Assessment of Coronary Hemodynamics and Vascular Function

“…28,29 Although endothelial dysfunction may be indicated by several biomarkers, the vasodilation of blood vessel in response to endothelium-dependent agonists is the gold standard. 30 For in vitro studies, the wire and pressure myographs have been used extensively to study the vasoreactivity and pharmacology of the large and small vessels, respectively. [31][32][33] The wire myograph is used in studies with vessels a diameter range from large vessels (aorta) down to about 500 μm.…”

Regulation of 130-kDa Smooth Muscle Myosin Light Chain Kinase Expression by an Intronic CArG Element

“…A pressure transducer (SPR-524, Microtip catheter transducer, Millar) was used to monitor the intraluminal pressure, and a volume compensator was used to compensate for water transport across the vessel wall. The vascular contraction during endothelin 1 stimulation was measured as changes in intraluminal pressure (36).…”