Blood pressure regulation V: in vivo mechanical properties of precapillary vessels as affected by long-term pressure loading and unloading
2014 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 114, no 3, 499-509 p.Article, review/survey (Refereed) Published
Recent studies are reviewed, concerning the in vivo wall stiffness of arteries and arterioles in healthy humans, and how these properties adapt to iterative increments or sustained reductions in local intravascular pressure. A novel technique was used, by which arterial and arteriolar stiffness were determined as changes in arterial diameter and flow, respectively, during graded increments in distending pressure in the blood vessels of an arm or a leg. Pressure-induced increases in diameter and flow were smaller in the lower leg than in the arm, indicating greater stiffness in the arteries/arterioles of the leg. A 5-wk period of intermittent intravascular pressure elevations in one arm reduced pressure distension and pressure-induced flow in the brachial artery by about 50%. Conversely, prolonged reduction of arterial/arteriolar pressure in the lower body by 5 wks of sustained horizontal bedrest, induced three-fold increases of the pressure-distension and pressure-flow responses in a tibial artery. Thus, the wall stiffness of arteries and arterioles are plastic properties that readily adapt to changes in the prevailing local intravascular pressure. The discussion concerns mechanisms underlying changes in local arterial/arteriolar stiffness as well as whether stiffness is altered by changes in myogenic tone and/or wall structure. As regards implications, regulation of local arterial/arteriolar stiffness may facilitate control of arterial pressure in erect posture and conditions of exaggerated intravascular pressure gradients. That increased intravascular pressure leads to increased arteriolar wall stiffness also supports the notion that local pressure loading may constitute a prime mover in the development of vascular changes in hypertension.
Place, publisher, year, edition, pages
2014. Vol. 114, no 3, 499-509 p.
Arterial compliance, Hypotension, Peripheral blood-flow resistance, Vascular deconditioning, Vascular remodelling, Vascular wall tension
IdentifiersURN: urn:nbn:se:kth:diva-134195DOI: 10.1007/s00421-013-2758-9ISI: 000331650900006ScopusID: 2-s2.0-84894659272OAI: oai:DiVA.org:kth-134195DiVA: diva2:665275
QC 201506222013-11-192013-11-192015-06-22Bibliographically approved