Am. J. Respir. Crit. Care Med., Volume 160, Number 3, September 1999, 942-949

Surfactant Proteins A and D in Premature Baboons with Chronic Lung Injury (Bronchopulmonary Dysplasia)
Evidence for an Inhibition of Secretion

SHANJANA AWASTHI, JACQUELINE J. COALSON, ERIKA CROUCH, FUNMAI YANG, and RICHARD J. KING

Departments of Physiology, Cell and Structural Biology, and Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas; and Department of Pathology, Washington University, St. Louis, Missouri

Surfactant proteins A and D (SP-A and SP-D) are believed to participate in the pulmonary host defense and the response to lung injury. In order to understand the effects of prematurity and lung injury on these proteins, we measured the amounts of SP-A and SP-D and their mRNAs in three groups of animals: (1) nonventilated premature baboon fetuses; (2) neonatal baboons delivered prematurely at 140 d gestation age (ga) and ventilated with PRN O₂; (3) animals of the same age ventilated with 100% O₂ to induce chronic lung injury. In nonventilated fetuses, tissue and lavage SP-A were barely detectable in baboons of 125 and 140 d ga, but they equaled or exceeded adult SP-A concentrations (g/g lung dry wt) at 175 d (term gestation, 185 d). In contrast, SP-D was readily detectable in tissue and lavage at 125 and 140 d ga. When the baboons of 140 d ga were ventilated for 10 d with 100% oxygen to produce chronic lung injury, the tissue concentration of SP-A was five times greater than that of normal adults; SP-D 16-times greater. Despite the sizable tissue pools of SP-A and SP-D, however, lavage SP-A was only 7% of that of normal adults and lavage SP-D just equaled the amount in normal adults. Nevertheless, because SP-D is normally in much lower concentration than is SP-A, their total comprised less than 12% of the SP-A and SP-D found in the lavage of a healthy adult. The results indicate that in chronic lung injury, SP-A is significantly reduced in the alveolar space. SP-D concentration in lavage is about equal to that in normal adults, possibly because of the 16-fold excess in tissue, but the total collectin pool in lavage is still significantly reduced. Because these collectins may bind and opsonize bacteria and viruses, decrements in their amounts may present additional risk to those premature infants who require prolonged periods of ventilatory support.

This article has been cited by other articles:

				M. Ikegami, E. A. Scoville, S. Grant, T. Korfhagen, W. Brondyk, R. K. Scheule, and J. A. Whitsett Surfactant Protein-D and Surfactant Inhibit Endotoxin-Induced Pulmonary Inflammation Chest, November 1, 2007; 132(5): 1447 - 1454. [Abstract] [Full Text] [PDF]

				H. R. S. Tagaram, G. Wang, T. M. Umstead, A. N. Mikerov, N. J. Thomas, G. R. Graff, J. C. Hess, M. J. Thomassen, M. S. Kavuru, D. S. Phelps, et al. Characterization of a human surfactant protein A1 (SP-A1) gene-specific antibody; SP-A1 content variation among individuals of varying age and pulmonary health Am J Physiol Lung Cell Mol Physiol, May 1, 2007; 292(5): L1052 - L1063. [Abstract] [Full Text] [PDF]

				M. Ikegami, K. Carter, K. Bishop, A. Yadav, E. Masterjohn, W. Brondyk, R. K. Scheule, and J. A. Whitsett Intratracheal Recombinant Surfactant Protein D Prevents Endotoxin Shock in the Newborn Preterm Lamb Am. J. Respir. Crit. Care Med., June 15, 2006; 173(12): 1342 - 1347. [Abstract] [Full Text] [PDF]

				C. L. S. George, M. L. White, M. E. O'Neill, P. S. Thorne, D. A. Schwartz, and J. M. Snyder Altered surfactant protein A gene expression and protein metabolism associated with repeat exposure to inhaled endotoxin Am J Physiol Lung Cell Mol Physiol, December 1, 2003; 285(6): L1337 - L1344. [Abstract] [Full Text] [PDF]

				T. J. M. MOSS, J. P. NEWNHAM, K. E. WILLETT, B. W. KRAMER, A. H. JOBE, and M. IKEGAMI Early Gestational Intra-Amniotic Endotoxin . Lung Function, Surfactant, and Morphometry Am. J. Respir. Crit. Care Med., March 15, 2002; 165(6): 805 - 811. [Abstract] [Full Text] [PDF]

				J. M. Klein, T. A. McCarthy, J. M. Dagle, and J. M. Snyder Pre- and Postnatal Lung Development, Maturation, and Plasticity: Antisense inhibition of surfactant protein A decreases tubular myelin formation in human fetal lung in vitro Am J Physiol Lung Cell Mol Physiol, March 1, 2002; 282(3): L386 - L393. [Abstract] [Full Text] [PDF]

				A. M. LeVine, K. Hartshorn, J. Elliott, J. Whitsett, and T. Korfhagen Absence of SP-A modulates innate and adaptive defense responses to pulmonary influenza infection Am J Physiol Lung Cell Mol Physiol, March 1, 2002; 282(3): L563 - L572. [Abstract] [Full Text] [PDF]

				B. W. KRAMER, M. IKEGAMI, and A. H. JOBE Intratracheal Endotoxin Causes Systemic Inflammation in Ventilated Preterm Lambs Am. J. Respir. Crit. Care Med., February 15, 2002; 165(4): 463 - 469. [Abstract] [Full Text] [PDF]

				A. M. LeVine, J. A. Whitsett, K. L. Hartshorn, E. C. Crouch, and T. R. Korfhagen Surfactant Protein D Enhances Clearance of Influenza A Virus from the Lung In Vivo J. Immunol., November 15, 2001; 167(10): 5868 - 5873. [Abstract] [Full Text] [PDF]

				N. Zafar, C. M. Wallace, P. Kieffer, P. Schroeder, M. Schootman, and A. Hamvas Improving Survival of Vulnerable Infants Increases Neonatal Intensive Care Unit Nosocomial Infection Rate Arch Pediatr Adolesc Med, October 1, 2001; 155(10): 1098 - 1104. [Abstract] [Full Text] [PDF]

				C. W. White, K. E. Greene, C. B. Allen, and J. M. Shannon Elevated Expression of Surfactant Proteins in Newborn Rats during Adaptation to Hyperoxia Am. J. Respir. Cell Mol. Biol., July 1, 2001; 25(1): 51 - 59. [Abstract] [Full Text] [PDF]

				S. AWASTHI, J. J. COALSON, B. A. YODER, E. CROUCH, and R. J. KING Deficiencies in Lung Surfactant Proteins A and D Are Associated with Lung Infection in Very Premature Neonatal Baboons Am. J. Respir. Crit. Care Med., February 1, 2001; 163(2): 389 - 397. [Abstract] [Full Text]

				K. R. KHUBCHANDANI and J. M. SNYDER Surfactant protein A (SP-A): the alveolus and beyond FASEB J, January 1, 2001; 15(1): 59 - 69. [Abstract] [Full Text] [PDF]

				B. W. KRAMER, A. H. JOBE, C. J. BACHURSKI, and M. IKEGAMI Surfactant Protein A Recruits Neutrophils into the Lungs of Ventilated Preterm Lambs Am. J. Respir. Crit. Care Med., January 1, 2001; 163(1): 158 - 165. [Abstract] [Full Text]