Am. J. Respir. Crit. Care Med., Volume 156, Number 2, August 1997, 624-630

Prenatal Glucocorticoid and T₄ Effects on Lung Morphology in Preterm Lambs

KENT E. PINKERTON, KAREN E. WILLET, JANICE L. PEAKE, PETER D. SLY, ALAN H. JOBE, and MACHIKO IKEGAMI

Department of Anatomy, Physiology, and Cell Biology, California Regional Primate Research Center, School of Veterinary Medicine, University of California, Davis, California; Division of Clinical Sciences, Institute for Child Health Research, Perth, Western Australia; Perinatal Research Laboratories, Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, California

Prenatal glucocorticoid plus T₄ treatment of fetal sheep results in improvements in oxygenation, gas exchange, lung mechanics, and lung volumes after preterm delivery. We have evaluated the morphometric changes in the lungs of lambs exposed to betamethasone and T₄ 48 h before preterm delivery at 121 and 135 d gestation and related those changes to the physiologic improvements in lung function. The lungs used for the morphometric studies were from lambs with postnatal physiologic responses similar to those of the entire group of lambs reported previously (). At both 121 and 135 d gestation, lung gas volumes and fixed tissue volumes increased, the percent of collapsed (nonaerated) parenchyma decreased, and the percent of perilobular connective tissue decreased with both gestational age and prenatal hormone exposure. Alveolar size, as estimated by mean linear intercept length, did not change with gestation or hormone exposure, but there was a decrease in alveolar wall thickness with advancing gestation and at each gestation with hormone exposure. The major anatomic effect of prenatal hormone exposure was a decrease in alveolar wall thickness and an increase in aerated parenchyma, effects that were consistent with the physiologic improvements in postnatal lung function.

This article has been cited by other articles:

				G. A. Agrons, S. E. Courtney, J. T. Stocker, and R. I. Markowitz From the Archives of the AFIP: Lung Disease in Premature Neonates: Radiologic-Pathologic Correlation RadioGraphics, July 1, 2005; 25(4): 1047 - 1073. [Abstract] [Full Text] [PDF]

				H. W. Chu, S. Balzar, G. J. Seedorf, J. Y. Westcott, J. B. Trudeau, P. Silkoff, and S. E. Wenzel Transforming Growth Factor-{beta}2 Induces Bronchial Epithelial Mucin Expression in Asthma Am. J. Pathol., October 1, 2004; 165(4): 1097 - 1106. [Abstract] [Full Text] [PDF]

				K. E. WILLET, A. H. JOBE, M. IKEGAMI, J. KOVAR, and P. D. SLY Lung Morphometry after Repetitive Antenatal Glucocorticoid Treatment in Preterm Sheep Am. J. Respir. Crit. Care Med., May 1, 2001; 163(6): 1437 - 1443. [Abstract] [Full Text]

				C. J. Bachurski, G. F. Ross, M. Ikegami, B. W. Kramer, and A. H. Jobe Intra-amniotic endotoxin increases pulmonary surfactant proteins and induces SP-B processing in fetal sheep Am J Physiol Lung Cell Mol Physiol, February 1, 2001; 280(2): L279 - L285. [Abstract] [Full Text] [PDF]

				A. H. JOBE, J. P. NEWNHAM, K. E. WILLET, T. J. MOSS, M. GORE ERVIN, J. F. PADBURY, P. SLY, and M. IKEGAMI Endotoxin-induced Lung Maturation in Preterm Lambs Is Not Mediated by Cortisol Am. J. Respir. Crit. Care Med., November 1, 2000; 162(5): 1656 - 1661. [Abstract] [Full Text]

				K. E. WILLET, A. H. JOBE, M. IKEGAMI, J. NEWNHAM, and P. D. SLY Pulmonary Interstitial Emphysema 24 Hours after Antenatal Betamethasone Treatment in Preterm Sheep Am. J. Respir. Crit. Care Med., September 1, 2000; 162(3): 1087 - 1094. [Abstract] [Full Text]

				R. C. Tan, M. Ikegami, A. H. Jobe, L. Y. Yao, F. Possmayer, and P. L. Ballard Developmental and glucocorticoid regulation of surfactant protein mRNAs in preterm lambs Am J Physiol Lung Cell Mol Physiol, December 1, 1999; 277(6): L1142 - L1148. [Abstract] [Full Text] [PDF]