Document Detail

Biaxial vasoactivity of porcine coronary artery.
MedLine Citation:
PMID:  22427520     Owner:  NLM     Status:  MEDLINE    
The passive mechanical properties of blood vessel mainly stem from the interaction of collagen and elastin fibers, but vessel constriction is attributed to smooth muscle cell (SMC) contraction. Although the passive properties of coronary arteries have been well characterized, the active biaxial stress-strain relationship is not known. Here, we carry out biaxial (inflation and axial extension) mechanical tests in right coronary arteries that provide the active coronary stress-strain relationship in circumferential and axial directions. Based on the measurements, a biaxial active strain energy function is proposed to quantify the constitutive stress-strain relationship in the physiological range of loading. The strain energy is expressed as a Gauss error function in the physiological pressure range. In K(+)-induced vasoconstriction, the mean ± SE values of outer diameters at transmural pressure of 80 mmHg were 3.41 ± 0.17 and 3.28 ± 0.24 mm at axial stretch ratios of 1.3 and 1.5, respectively, which were significantly smaller than those in Ca(2+)-free-induced vasodilated state (i.e., 4.01 ± 0.16 and 3.75 ± 0.20 mm, respectively). The mean ± SE values of the inner and outer diameters in no-load state and the opening angles in zero-stress state were 1.69 ± 0.04 mm and 2.25 ± 0.08 mm and 126 ± 22°, respectively. The active stresses have a maximal value at the passive pressure of 80-100 mmHg and at the active pressure of 140-160 mmHg. Moreover, a mechanical analysis shows a significant reduction of mean stress and strain (averaged through the vessel wall). These findings have important implications for understanding SMC mechanics.
Yunlong Huo; Yana Cheng; Xuefeng Zhao; Xiao Lu; Ghassan S Kassab
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2012-03-16
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  302     ISSN:  1522-1539     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2012 May 
Date Detail:
Created Date:  2012-05-16     Completed Date:  2012-07-26     Revised Date:  2013-06-26    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H2058-63     Citation Subset:  IM    
Department of Biomedical Engineering, Indiana University-Perdue University Indianapolis, Indianapolis, IN 46202, USA.
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MeSH Terms
Blood Pressure / physiology
Coronary Vessels / physiology*
Elasticity / physiology
Models, Animal
Models, Cardiovascular*
Stress, Mechanical*
Vasoconstriction / physiology
Vasodilation / physiology
Vasomotor System / physiology*
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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