Vol. 282, Issue 6, H2364-H2370, June 2002
Different 
-adrenoceptors mediate migration of vascular
smooth muscle cells and adventitial fibroblasts in vitro
Hua
Zhang1,
Carie S.
Facemire1,
Albert J.
Banes2, and
James E.
Faber1
Departments of 1 Cell and Molecular Physiology and
2 Orthopedics, School of Medicine, University of
North Carolina, Chapel Hill, North Carolina 27599
Norepinephrine directly induces growth of
the vascular wall, which may involve not only proliferation of smooth
muscle cells (SMCs) and adventitial fibroblasts (AFBs) but also
augmentation of their migration. To test this hypothesis,
growth-arrested SMCs and AFBs from rat aorta were exposed to
norepinephrine. Norepinephrine caused dose-dependent migration of both
cell types that was dependent on chemotaxis. In contrast,
platelet-derived growth factor (PDGF)-BB, used as a positive control,
stimulated both chemotaxis and chemokinesis. Only
1D-adrenoceptors (AR) and 2-AR
antagonists inhibited norepinephrine migration of SMCs, whereas
norepinephrine migration of AFBs was only inhibited by
1A-AR and 1B-AR antagonists; 
-AR
blockade was without effect. Norepinephrine and PDGF-BB were additive
for AFB, but not SMC, migration. Stimulation of migration was reversed at high norepinephrine concentrations (10 µM); this inhibition was
mediated by 2- and -ARs in AFBs but not in SMCs. Thus
norepinephrine induces migration of SMCs and AFBs via different
-ARs. This action may participate in wall remodeling and
norepinephrine potentiation of injury-induced intimal lesion growth.
artery; adrenergic receptor; growth; remodeling; platelet-derived
growth factor
