This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Boutouyrie, P. Articles by Laurent, S. Search for Related Content PubMed PubMed Citation Articles by Boutouyrie, P. Articles by Laurent, S.

(Hypertension. 1998;32:360-364.)
© 1998 American Heart Association, Inc.

Third Workshop on Structure and Function of Large Arteries: Part II

Smooth Muscle Tone and Arterial Wall Viscosity

An In Vivo/In Vitro Study

Pierre Boutouyrie; Saliha Boumaza; Pascal Challande; Patrick Lacolley; ; Stéphane Laurent

From the Department of Pharmacology, Hôpital Broussais (P.B., S.L.), and INSERM U337 (S.B., P.L., S.L.) Paris, and URA-CNRS 879 (P.C.), Saint Cyr l'Ecole, France.

Abstract

Abstract—The relationships between steady and pulsatile pressures, smooth muscle tone, and arterial viscoelastic behavior remain a matter of controversy. We previously showed that arterial wall viscosity (AWV) was 3-fold lower in vivo than in vitro and suggested that in vivo active mechanisms could minimize intrinsic AWV to improve the efficiency of heart-vessel coupling energy balance. The aim of the present study was to determine the role of smooth muscle tone on AWV, under various levels of steady and pulsatile pressures, both in vivo and in vitro. AWV of rat abdominal aorta was studied first in vivo after bolus injections of phenylephrine (PE) or sodium nitroprusside (SNP), then in vitro in response to PE or SNP. In vitro, arterial segments were submitted first to steady pressure (0 to 200 mm Hg) by increments of 20 mm Hg, then to increasing levels of pulse pressure (20 to 50 mm Hg) at various mean arterial pressures (75 to 150 mm Hg). AWV was quantified as the area of the pressure/diameter relationship hysteresis, issued from the simultaneous measurements of pressure (Millar micromanometer) and diameter (NIUS echotracking device). In vivo, AWV increased after PE and decreased after SNP, in parallel with pressure changes. In vitro, AWV was not significantly influenced by PE and SNP. After both PE and SNP, AWV increased with pulse pressure but was not influenced by mean arterial pressure. At any given pulse pressure, AWV was higher in vitro than in vivo. The relation between AWV and pulse pressure was significantly steeper in vitro than in vivo. These results show that AWV is strongly influenced by steady and pulsatile mechanical load but not by smooth muscle tone, both in vivo and in vitro. Factors other than sustained smooth muscle activation should be explored to explain the minimization of AWV in vivo compared with intrinsic in vitro values.

Key Words: viscosity • arteries • muscle, smooth • sodium nitroprusside • phenylephrine • aorta

This article has been cited by other articles:

				R. L. Prantil, R. J. Jankowski, Y. Kaiho, W. C. de Groat, M. B. Chancellor, N. Yoshimura, and D. A. Vorp Ex vivo biomechanical properties of the female urethra in a rat model of birth trauma Am J Physiol Renal Physiol, April 1, 2007; 292(4): F1229 - F1237. [Abstract] [Full Text] [PDF]

				R. L. Armentano, J. G. Barra, D. B. Santana, F. M. Pessana, S. Graf, D. Craiem, L. M. Brandani, H. P. Baglivo, and R. A. Sanchez Smart Damping Modulation of Carotid Wall Energetics in Human Hypertension: Effects of Angiotensin-Converting Enzyme Inhibition Hypertension, March 1, 2006; 47(3): 384 - 390. [Abstract] [Full Text] [PDF]

				T. Wronski, E. Seeliger, P. B. Persson, A. Harnath, and B. Flemming Influence of baroreflex on volume elasticity of heart and aorta in the rabbit Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2002; 282(3): R842 - R849. [Abstract] [Full Text] [PDF]

				P. Lacolley, P. Challande, S. Boumaza, G. Cohuet, S. Laurent, P. Boutouyrie, J.-A. Grimaud, D. Paulin, J.-M. D. Lamaziere, and Z. Li Mechanical properties and structure of carotid arteries in mice lacking desmin Cardiovasc Res, July 1, 2001; 51(1): 178 - 187. [Abstract] [Full Text] [PDF]

				E. D. Frohlich The necessity for recognition and treatment of patients with "mild" hypertension J. Am. Coll. Cardiol., November 1, 1999; 34(5): 1369 - 1377. [Abstract] [Full Text] [PDF]

				L. Mircoli, A. A. Mangoni, C. Giannattasio, G. Mancia, and A. U. Ferrari Heart Rate-Dependent Stiffening of Large Arteries in Intact and Sympathectomized Rats Hypertension, October 1, 1999; 34(4): 598 - 602. [Abstract] [Full Text] [PDF]

				E. I. Cabrera Fischer, R. L. Armentano, F. M. Pessana, S. Graf, L. Romero, A. I. Christen, A. Simon, and J. Levenson Endothelium-dependent arterial wall tone elasticity modulated by blood viscosity Am J Physiol Heart Circ Physiol, February 1, 2002; 282(2): H389 - H394. [Abstract] [Full Text] [PDF]