Articles |
the Department of Pathology, Cardiovascular Research Institute Maastricht, University of Limburg, Maastricht, Netherlands, and the Pharma Division (J.F.), Preclinical Research, F Hoffmann-La Roche Ltd, Basel, Switzerland.
Correspondence to Mat J.A.P. Daemen, Department of Pathology, University of Limburg, PO Box 616, 6200 MD Maastricht, Netherlands. E-mail MDA@ms.azm.2.azm.nl.
To investigate the relative importance of AT1 and AT2 receptors in angiotensin II (Ang II)-induced restimulation of neointimal smooth muscle cell (SMC) DNA synthesis and increased neointimal cross-sectional area (CSA), male Wistar rats were subcutaneously infused for 2 weeks with Ang II and losartan, an AT1 receptor antagonist, or Ang II and PD123319, an AT2 receptor antagonist, during the third and fourth week after balloon injury of the left common carotid artery. Concomitantly, all rats received 5-bromo-2'-deoxyuridine to label DNA-synthesizing SMCs. Neointimal CSAs and SMC DNA synthesis were compared with control groups that received Ang II, 0.9% NaCl, losartan, or PD123319. Systolic blood pressure (SBP) was measured at different times during the infusion. Ang II induced an increase in SBP that was significantly different from the SBP in the NaCl group. Infusion of Ang II together with losartan reduced the Ang II-induced increase in SBP to levels comparable with those obtained in the NaCl group. Infusion of Ang II+PD123319 caused an increase in SBP that was comparable with the increase in SBP of the Ang II group and significantly different from the SBP of the NaCl group. Infusion of losartan or PD123319 alone did not affect SBP. Ang II significantly enhanced neointimal CSA (47%, P<.05) compared with the control group infused with NaCl. Losartan significantly reduced Ang II-induced neointimal thickening (neointimal CSA, -37%, P<.05). Infusion of PD123319 together with Ang II did not affect Ang II-induced neointimal thickening. Losartan or PD123319 alone did not reduce neointimal thickening, since the neointimal CSAs in these groups did not differ from the neointimal CSA of the NaCl group. Comparable effects were found for SMC DNA synthesis in the neointima. Ang II infusion increased neointimal SMC DNA synthesis. Addition of losartan reduced the fraction of DNA-synthesizing neointimal SMCs from 23.7±2.1% in the Ang II group to 12.8±1.8% in the Ang II+losartan group, whereas the labeling fraction in the neointima remained 26.6±3.1% in the Ang II+PD123319 group. The labeling fractions in the neointimas of the groups that received losartan or PD123319 alone did not differ from the labeling fraction in the NaCl group. These data indicate that AT1 but not AT2 receptors mediate the progression of neointimal thickening induced by delayed application of Ang II in the injured left carotid artery in the rat. Furthermore, these data suggest that AT1 and AT2 receptors are not involved in the regulation of normal growth of a neointima in the third and fourth week after balloon injury.
Key Words: restenosis balloon injury growth control AT receptor antagonists
This article has been cited by other articles:
![]() |
T. A. Barker, M. P. Massett, V. A. Korshunov, A. M. Mohan, A. J. Kennedy, and B. C. Berk Angiotensin II Type 2 Receptor Expression After Vascular Injury: Differing Effects of Angiotensin-Converting Enzyme Inhibition and Angiotensin Receptor Blockade Hypertension, November 1, 2006; 48(5): 942 - 949. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Li, C. Zhang, S. Schaefer, A. Estes, and K. U. Malik ANG II-induced neointimal growth is mediated via cPLA2- and PLD2-activated Akt in balloon-injured rat carotid artery Am J Physiol Heart Circ Physiol, December 1, 2005; 289(6): H2592 - H2601. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Hafizi, X. Wang, A. H. Chester, M. H. Yacoub, and C. G. Proud ANG II activates effectors of mTOR via PI3-K signaling in human coronary smooth muscle cells Am J Physiol Heart Circ Physiol, September 1, 2004; 287(3): H1232 - H1238. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Yousufuddin, S. Haji, R. C. Starling, E. M. Tuzcu, N. B. Ratliff, D. J. Cook, A. Abdo, Y. Saad, S. S. Karnik, D. Wang, et al. Cardiac angiotensin II receptors as predictors of transplant coronary artery disease following heart transplantation Eur. Heart J., March 1, 2004; 25(5): 377 - 385. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Berl Angiotensin-Converting Enzyme Inhibitors versus AT1 Receptor Antagonist in Cardiovascular and Renal Protection: The case for AT1 Receptor Antagonist J. Am. Soc. Nephrol., January 1, 2004; 15(90010): S71 - 76. [Abstract] [Full Text] |
||||
![]() |
D. Henrion, N. Kubis, and B. I. Levy Physiological and Pathophysiological Functions of the AT2 Subtype Receptor of Angiotensin II: From Large Arteries to the Microcirculation Hypertension, November 1, 2001; 38(5): 1150 - 1157. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Lutgens, E. D. de Muinck, S. Heeneman, and M. J.A.P. Daemen Compensatory Enlargement and Stenosis Develop in ApoE-/- and ApoE*3-Leiden Transgenic Mice Arterioscler Thromb Vasc Biol, August 1, 2001; 21(8): 1359 - 1365. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. C. Berk Vascular Smooth Muscle Growth: Autocrine Growth Mechanisms Physiol Rev, July 1, 2001; 81(3): 999 - 1030. [Abstract] [Full Text] [PDF] |
||||
![]() |
B.-S. Tea, S. Der Sarkissian, R. M. Touyz, P. Hamet, and D. deBlois Proapoptotic and Growth-Inhibitory Role of Angiotensin II Type 2 Receptor in Vascular Smooth Muscle Cells of Spontaneously Hypertensive Rats In Vivo Hypertension, May 1, 2000; 35(5): 1069 - 1073. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Lemay, P. Hamet, and D. deBlois Losartan-induced apoptosis as a novel mechanism for the prevention of vascular lesion formation after injury Journal of Renin-Angiotensin-Aldosterone System, March 1, 2000; 1(1): 46 - 50. [Abstract] [PDF] |
||||
![]() |
F. L. Day, L. A. Rafty, C. N. Chesterman, and L. M. Khachigian Angiotensin II (ATII)-inducible Platelet-derived Growth Factor A-chain Gene Expression Is p42/44 Extracellular Signal-regulated Kinase-1/2 and Egr-1-dependent and Mediated via the ATII Type 1 but Not Type 2 Receptor. INDUCTION BY ATII ANTAGONIZED BY NITRIC OXIDE J. Biol. Chem., August 20, 1999; 274(34): 23726 - 23733. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. P. Wilson, L. Saward, P. Zahradka, and P. Kee Cheung Angiotensin II receptor antagonists prevent neointimal proliferation in a porcine coronary artery organ culture model Cardiovasc Res, June 1, 1999; 42(3): 761 - 772. [Abstract] [Full Text] [PDF] |
||||
![]() |
X.-P. Xi, K. Graf, S. Goetze, E. Fleck, W. A. Hsueh, and R. E. Law Central Role of the MAPK Pathway in Ang II–Mediated DNA Synthesis and Migration in Rat Vascular Smooth Muscle Cells Arterioscler Thromb Vasc Biol, January 1, 1999; 19(1): 73 - 82. [Abstract] [Full Text] [PDF] |
||||
|
ATVB Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1996 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |