Gj. Poiani et al., EFFECT OF GLUCOCORTICOIDS ON COLLAGEN ACCUMULATION IN PULMONARY VASCULAR REMODELING IN THE RAT, American journal of respiratory and critical care medicine, 149(4), 1994, pp. 994-999
Citations number
36
Categorie Soggetti
Emergency Medicine & Critical Care","Respiratory System
Administration of corticosteroids may attenuate the development of pul
monary hypertension by inhibiting the cell proliferation and protein s
ynthesis that occur in early pulmonary vascular remodeling. However, i
n vitro studies show that corticosteroids stimulate collagen synthesis
in vascular smooth muscle cells, and corticosteroid administration ma
y be deleterious in stimulating collagen deposition. To test whether c
orticosteroid treatment promotes vascular collagen production in vivo,
we administered triamcinolone diacetate to rats exposed to 10% O-2 fo
r 3 days and measured pro alpha 1(l) collagen mRNA and the hydroxyprol
ine/protein ratio in the main pulmonary artery. Triamcinolone treatmen
t (12 mg/kg intraperitoneally, once daily for 3 days) reduced mean rig
ht ventricular pressure (11 +/- 1 versus 14 +/- 1 mm Hg) and protein c
ontent of pulmonary arteries (1.8 +/- 0.1 versus 2.7 +/- 0.1 mg/vessel
) (both p < 0.05). However, corticosteroid treatment produced a dose-r
elated increase in pro alpha 1(l) mRNA levels and increased the ratio
of hydroxyproline/protein (47 +/- 2 versus 38 +/- 3 mu g/mg; p < 0.05)
. Thus, corticosteroid administration ameliorated the increase in pulm
onary hypertension in early hypoxia, but increased the proportion of c
ollagen in the vessel wall. Corticosteroid treatment in pulmonary vasc
ular remodeling may be deleterious in increasing the concentration of
collagen in the vessel wall.