AJP - Lung Cellular and Molecular Physiology, Vol 265, Issue 4 403-L409, Copyright © 1993 by American Physiological Society

ARTICLES

Changes in lung expansion alter pulmonary DNA synthesis and IGF-II gene expression in fetal sheep

S. B. Hooper, V. K. Han and R. Harding
Department of Physiology, Monash University, Clayton, Victoria, Australia.

Our aim was to determine the effect of short-term (7 days) alterations in fetal lung liquid volume on pulmonary DNA synthesis rates and insulin-like growth factor-II (IGF-II) mRNA levels. Fifteen chronically catheterized fetal sheep were divided into three groups. In one, the trachea was obstructed, in another lung liquid was drained by gravity, and the third group served as controls. After 7 days, [3H]thymidine was injected into each fetus and 8 h later fetal tissues were collected. Fetal lung-to-body weight ratios and total lung DNA contents were greatly increased in fetuses with tracheal obstruction compared with control fetuses, whereas the drainage of lung liquid did not affect these measurements. DNA synthesis rates in pulmonary tissue were significantly reduced from a mean control value of 153.3 +/- 25.1 disintegrations per minute (dpm)/microgram DNA to 57.2 +/- 8.6 dpm/microgram DNA by lung liquid drainage (P < 0.05) and were significantly increased to 236.0 +/- 24.0 dpm/microgram DNA by tracheal obstruction (P < 0.05). Following tracheal obstruction, lung IGF-II mRNA levels were increased to 177.0 +/- 18.2% (P < 0.05) of the mean value for control fetuses, whereas they were reduced to 56.1 +/- 7.1% of control in lung liquid-drained fetuses. We conclude that altering fetal lung expansion has a potent and rapid effect on pulmonary DNA synthesis and that this effect may, in part, be mediated by an alteration in IGF-II gene expression.

This article has been cited by other articles:

				F. Sozo, S. B. Hooper, and M. J. Wallace Thrombospondin-1 expression and localization in the developing ovine lung J. Physiol., October 15, 2007; 584(2): 625 - 635. [Abstract] [Full Text] [PDF]

				O. Boucherat, A. Benachi, A.-M. Barlier-Mur, M.-L. Franco-Montoya, J. Martinovic, B. Thebaud, B. Chailley-Heu, and J. R. Bourbon Decreased Lung Fibroblast Growth Factor 18 and Elastin in Human Congenital Diaphragmatic Hernia and Animal Models Am. J. Respir. Crit. Care Med., May 15, 2007; 175(10): 1066 - 1077. [Abstract] [Full Text] [PDF]

				S. J. Flecknoe, K. J. Crossley, G. M. Zuccala, J. E. Searle, B. J. Allison, M. J. Wallace, and S. B. Hooper Increased lung expansion alters lung growth but not alveolar epithelial cell differentiation in newborn lambs Am J Physiol Lung Cell Mol Physiol, February 1, 2007; 292(2): L454 - L461. [Abstract] [Full Text] [PDF]

				G. R. Polglase, M. J. Wallace, D. L. Morgan, and S. B. Hooper Increases in lung expansion alter pulmonary hemodynamics in fetal sheep J Appl Physiol, July 1, 2006; 101(1): 273 - 282. [Abstract] [Full Text] [PDF]

				C. E. Filby, S. B. Hooper, F. Sozo, V. A. Zahra, S. J. Flecknoe, and M. J. Wallace VDUP1: a potential mediator of expansion-induced lung growth and epithelial cell differentiation in the ovine fetus Am J Physiol Lung Cell Mol Physiol, February 1, 2006; 290(2): L250 - L258. [Abstract] [Full Text] [PDF]

				F. Sozo, M. J. Wallace, V. A. Zahra, C. E. Filby, and S. B. Hooper Gene expression profiling during increased fetal lung expansion identifies genes likely to regulate development of the distal airways Physiol Genomics, January 12, 2006; 24(2): 105 - 113. [Abstract] [Full Text] [PDF]

				J. Yoshizawa, C. J. Chapin, L. Sbragia, R. Ertsey, J. A. Gutierrez, C. T. Albanese, and J. A. Kitterman Tracheal occlusion stimulates cell cycle progression and type I cell differentiation in lungs of fetal rats Am J Physiol Lung Cell Mol Physiol, August 1, 2003; 285(2): L344 - L353. [Abstract] [Full Text] [PDF]

				Y. Kitano, D. Von Allmen, M. Kanai, T. M. Quinn, P. Davies, Y. Kitano, and A. W. Flake Fetal lung growth after short-term tracheal occlusion is linearly related to intratracheal pressure J Appl Physiol, February 1, 2001; 90(2): 493 - 500. [Abstract] [Full Text] [PDF]

				M. Liu and M. Post Cellular Responses to Mechanical Stress: Invited Review: Mechanochemical signal transduction in the fetal lung J Appl Physiol, November 1, 2000; 89(5): 2078 - 2084. [Abstract] [Full Text] [PDF]

				J. C. Schittny, G. Miserocchi, and M. P. Sparrow Spontaneous Peristaltic Airway Contractions Propel Lung Liquid through the Bronchial Tree of Intact and Fetal Lung Explants Am. J. Respir. Cell Mol. Biol., July 1, 2000; 23(1): 11 - 18. [Abstract] [Full Text]

				S. Flecknoe, R. Harding, G. Maritz, and S. B. Hooper Increased lung expansion alters the proportions of type I and type II alveolar epithelial cells in fetal sheep Am J Physiol Lung Cell Mol Physiol, June 1, 2000; 278(6): L1180 - L1185. [Abstract] [Full Text] [PDF]

				G. A. Braems, L.-J. Yao, K. Inchley, A. Brickenden, V. K. M. Han, A. Grolla, J. R. G. Challis, and F. Possmayer Ovine surfactant protein cDNAs: use in studies on fetal lung growth and maturation after prolonged hypoxemia Am J Physiol Lung Cell Mol Physiol, April 1, 2000; 278(4): L754 - L764. [Abstract] [Full Text] [PDF]

				L. Nardo, I. R. Young, and S. B. Hooper Influence of growth hormone on the lung growth response to tracheal obstruction in fetal sheep Am J Physiol Lung Cell Mol Physiol, March 1, 2000; 278(3): L453 - L459. [Abstract] [Full Text] [PDF]

				M. Liu, A. K. Tanswell, and M. Post Mechanical force-induced signal transduction in lung cells Am J Physiol Lung Cell Mol Physiol, October 1, 1999; 277(4): L667 - L683. [Abstract] [Full Text] [PDF]

				H. J PORTER Pulmonary hypoplasia Arch. Dis. Child. Fetal Neonatal Ed., September 1, 1999; 81(2): 81F - 83. [Full Text]

				J. A. Gutierrez, R. Ertsey, L. M. Scavo, E. Collins, and L. G. Dobbs Mechanical Distention Modulates Alveolar Epithelial Cell Phenotypic Expression by Transcriptional Regulation Am. J. Respir. Cell Mol. Biol., August 1, 1999; 21(2): 223 - 229. [Abstract] [Full Text]

				M. E. De Paepe, B. D. Johnson, K. Papadakis, and F. I. Luks Lung Growth Response after Tracheal Occlusion in Fetal Rabbits Is Gestational Age-Dependent Am. J. Respir. Cell Mol. Biol., July 1, 1999; 21(1): 65 - 76. [Abstract] [Full Text]

				M. P. Sparrow, M. Weichselbaum, and P. B. McCray Jr. Development of the Innervation and Airway Smooth Muscle in Human Fetal Lung Am. J. Respir. Cell Mol. Biol., April 1, 1999; 20(4): 550 - 560. [Abstract] [Full Text]

				A. Lines, L. Nardo, I. D. Phillips, F. Possmayer, and S. B. Hooper Alterations in lung expansion affect surfactant protein A, B, and C mRNA levels in fetal sheep Am J Physiol Lung Cell Mol Physiol, February 1, 1999; 276(2): L239 - L245. [Abstract] [Full Text] [PDF]

				R. E. Boland, L. Nardo, and S. B. Hooper Cortisol pretreatment enhances the lung growth response to tracheal obstruction in fetal sheep Am J Physiol Lung Cell Mol Physiol, December 1, 1997; 273(6): L1126 - L1131. [Abstract] [Full Text] [PDF]

				A. M. Gillett, M. J. Wallace, M. T. Gillespie, and S. B. Hooper Pre- and Postnatal Lung Development, Maturation, and Plasticity: Increased expansion of the lung stimulates calmodulin 2 expression in fetal sheep Am J Physiol Lung Cell Mol Physiol, March 1, 2002; 282(3): L440 - L447. [Abstract] [Full Text] [PDF]