AJP - Lung Cellular and Molecular Physiology, Vol 268, Issue 3 465-L470, Copyright © 1995 by American Physiological Society
Growth characteristics of pulmonary artery smooth muscle cells from fawn-hooded rats
K. Janakidevi, C. Tiruppathi, P. J. Del Vecchio, J. M. Pinheiro and A. B. Malik
Department of Physiology, Albany Medical College of Union University, New York 12208.
We compared the proliferative rates of vascular smooth muscle cells (VSMC)
from pulmonary arteries of pulmonary hypertensive fawn-hooded rats (FHR)
with VSMC from normotensive Sprague-Dawley rats (SDR). VSMC from FHR grew
at increased rates and reached higher densities at all serum concentrations
studied (5-20%) than the VSMC from SDR. The VSMC from FHR also responded to
epidermal growth factor (EGF) at low serum concentrations, as evidenced by
significantly greater DNA synthetic rates, than the control VSMC. The
increased growth in these cells could be due to increased number and/or
affinity of EGF receptors because of the higher specific binding of
125I-EGF to the VSMC from FHR. The VSMC from FHR and SDR were equally
sensitive to the antiproliferative effects of heparin, suggesting that the
heparin-sensitive pathways are not altered in the VSMC from FHR. These
results suggest that the development of pulmonary hypertension in FHR may
be related to the higher proliferative capacity of the pulmonary VSMC,
which may be coupled to increased activity of the EGF receptors on these
cells.
