| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Pediatric Heart Lung Center, Department of Pediatrics, 2 Cardiovascular Pulmonary Research Laboratory, Department of Medicine, and 3 Department of Radiological Sciences, University of Colorado School of Medicine, Denver, Colorado 80262
Dexamethasone (Dex) treatment during a critical period of lung development causes lung hypoplasia in infant rats. However, the effects of Dex on the pulmonary circulation are unknown. To determine whether Dex increases the risk for development of pulmonary hypertension, we treated newborn Sprague-Dawley rats with Dex (0.25 µg/day, days 3-13). Litters were divided equally between Dex-treated and vehicle control (ethanol) rats. Rats were raised in either room air until 10 wk of age (normoxic groups) or room air until 7 wk of age and then in a hypoxia chamber (inspired O2 fraction = 0.10; hypoxic groups) for 3 wk to induce pulmonary hypertension. Compared with vehicle control rats, Dex treatment of neonatal rats reduced alveolarization (by 42%; P < 0.05) and barium-filled pulmonary artery counts (by 37%; P < 0.05) in 10-wk-old adults. Pulmonary arterial pressure and the ratio of right ventricle to left ventricle plus septum weights (RV/LV+S) were higher in 10-wk-old Dex-treated normoxic rats compared with those in normoxic control rats (by 16 and 16% respectively; P < 0.05). Small pulmonary arteries of adult normoxic Dex-treated rats showed increased vessel wall thickness compared with that in control rats (by 15%; P < 0.05). After 3 wk of hypoxia, RV/LV+S values were 36% higher in rats treated with Dex in the neonatal period compared with those in hypoxic control rats (P < 0.05). RV/LV+S was 42% higher in hypoxic control rats compared with those in normoxic control rats (P < 0.05). We conclude that Dex treatment of neonatal rats caused sustained lung hypoplasia and increased pulmonary arterial pressures and augmented the severity of hypoxia-induced pulmonary hypertension in adult rats.
lung development; glucocorticoids; alveolarization; congenital diaphragmatic hernia; bronchopulmonary dysplasia; hypoxia
This article has been cited by other articles:
|
|
 |
|
  F. Ladha, S. Bonnet, F. Eaton, K. Hashimoto, G. Korbutt, and B. Thebaud Sildenafil Improves Alveolar Growth and Pulmonary Hypertension in Hyperoxia-induced Lung Injury Am. J. Respir. Crit. Care Med., September 15, 2005; 172(6): 750 - 756. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Massaro and G. D. Massaro Critical period for alveologenesis and early determinants of adult pulmonary disease Am J Physiol Lung Cell Mol Physiol, October 1, 2004; 287(4): L715 - L717. [Full Text] [PDF]
|
|
|
|
|
|
T. D. Le Cras, N. E. Markham, R. M. Tuder, N. F. Voelkel, and S. H. Abman Treatment of newborn rats with a VEGF receptor inhibitor causes pulmonary hypertension and abnormal lung structure Am J Physiol Lung Cell Mol Physiol, September 1, 2002; 283(3): L555 - L562. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Massaro and G. D. Massaro Pre- and Postnatal Lung Development, Maturation, and Plasticity: Invited Review: Pulmonary alveoli: formation, the "call for oxygen," and other regulators Am J Physiol Lung Cell Mol Physiol, March 1, 2002; 282(3): L345 - L358. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Jakkula, T. D. Le Cras, S. Gebb, K. P. Hirth, R. M. Tuder, N. F. Voelkel, and S. H. Abman Inhibition of angiogenesis decreases alveolarization in the developing rat lung Am J Physiol Lung Cell Mol Physiol, September 1, 2000; 279(3): L600 - L607. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
