Key result
Decreasing longitudinal stretch from lambda(z) = 1.8 to 1.4 halved distensibility at physiological pressures and resulted in significantly lower basal vascular smooth muscle contraction.
Why the study?
Does longitudinal stretch affect VSM tone and distensibility in muscular conduit arteries?
Does longitudinal stretch affect VSM tone and distensibility in muscular conduit arteries?
Decreasing longitudinal stretch in muscular conduit arteries halves distensibility and reduces basal VSM contraction, providing biomechanical insights into age-related arterial changes.
Answers are grounded in this paper and cite their sources.
Animal data link stretch to conduit artery mechanics; leaves open contribution to human age-related stiffening.
With progressing age, large arteries diminish their longitudinal stretch, which in extreme cases results in tortuosity. Increased age is also associated with loss of vessel distensibility. We measured pressure-diameter curves from muscular porcine carotid arteries ex vivo at different longitudinal stretch ratios (lambda(z) = 1.4 and 1.8) and under different vascular smooth muscle (VSM) conditions (fully relaxed, normal VSM tone, and maximally contracted). Distensibility was found to be halved by decreasing longitudinal stretch from lambda(z) = 1.8 to 1.4 at physiological pressures. This counterintuitive observation is possible because highly nonlinear elastic modulus of the artery and anisotropic properties. Furthermore, a significantly larger basal VSM contraction was observed at lambda(z) = 1.8 than 1.4, although this was clearly not related to a myogenic response during inflation. This dependence of VSM tone to longitudinal stretch may have possible implications on the functional characteristics of the arterial wall.
No takes yet. Share an insight, caveat, or question.
Zulliger et al. (2002) studied this question. Decreasing longitudinal stretch (lambda(z) = 1.4) vs. Longitudinal stretch lambda(z) = 1.8 was evaluated on Distensibility and vascular smooth muscle (VSM) tone. Decreasing longitudinal stretch from lambda(z) = 1.8 to 1.4 halved distensibility at physiological pressures and resulted in significantly lower basal vascular smooth muscle contraction.
Synapse has enriched 10 related papers. Consider them for comparative context: