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CARDIOVASCULAR
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Volume 6, 2001, No 1 |
Impact
of Nitric Oxide on Platelet-Derived Growth Factor Expression in Intrapulmonary
Arteries of Rats with Hypoxic Pulmonary Vascular Structural Remodeling
D. Junbao, Z. Bin, Z. Bin, T. Chaoshu
Objective:
To investigate the impact of nitric oxide (NO) on platelet-derived growth factor
(PDGF) expression in intrapulmonary arteries of rats with hypoxic pulmonary
vascular structural remodeling and to examine the possible mechanism responsible
for hypoxic pulmonary hypertension.
Methods:
Twenty-five male Wistar rats were randomly divided into four groups: nomoxic
group (n=6), hypoxic group (n=6), hypoxic + L-arginine group (hypoxic + L-Arg
group) (n=7) and hypoxic + Nw
-L-nitro-arginine methyl ester group (hypoxic + L-NAME group) (n=6). Relative
medial thickness (RMT) of small and median muscularized pulmonary arteries and
the percentage of muscularized arteries in small pulmonary arteries were
observed in lung sections of rats by using a light microscope.
Immunohistochemistry technique was used to assess the abundance and localization
of PDGF in intrapulmonary arteries of rats in four groups.
Results: RMT
of pulmonary arteries and the percentage of muscularized arteries in small
pulmonary arteries were obviously increased in hypoxic rats as compared with
normal controls (P<0.01). L-arginine significantly reduced RMT and the
percentage of muscularized arteries of chronically hypoxic rats (P<0.01).
L-NAME, however, markedly increased RMT and the percentage of muscularized
arteries of chronically hypoxic rats (P<0.01). There were PDGF expressions in
intrapulmonary artery endothelial cells and smooth muscle cells in four groups.
PDGF expressions were augmented in intrapulmonary artery endothelial cells and
smooth muscle cells in hypoxic rats as compared with normal controls
(P<0.01). L-Arg significantly inhibited the PDGF expressions by
intrapulmonary artery endothelial cells and smooth muscle cells in hypoxic rats.
However, L-NAME markedly strengthened the PDGF expressions by intrapulmonary
artery endothelial cells and smooth muscle cells. There was a positive
correlation between RMT and PDGF expression of endothelial cells and smooth
muscle cells of median pulmonary arteries (r=0.8636, 0.8264, P<0.01,
respectively). There was also a positive correlation between RMT and PDGF
expression of endothelial cells and smooth muscle cells of small pulmonary
arteries (r=0.8898, 0.8688, P<0.01, respectively).
Conclusion:
Nitric oxide inhibited PDGF expression in intrapulmonary arteries of rats with
hypoxic pulmonary vascular structural remodeling.
(CVE. 2001; 6 (1): 62-67)
Key words: Nitric oxide, Platelet-derived growth factor, Anoxia Pulmonary artery
Professor
Du Junbao, M.D.
Department of Pediatrics
First Hospital, Peking University
Xi-an Men Street No.1
Beijing, 100034
PR China
E-mail: junbaodu@ht.rol.cn.net
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