Journal of Applied Physiology, Vol 39, Issue 6 1017-1021, Copyright © 1975 by American Physiological Society

ARTICLES

Ontogeny of tracheal fluid, pulmonary surfactant, and plasma corticoids in the fetal lamb

E. J. Mescher, A. C. Platzker, P. L. Ballard, J. A. Kitterman, J. A. Clements and W. H. Tooley

We examined fetal plasma corticoids and flow rate, electrolyte composition, and surfactant content of tracheal fluid in chronic experiments with eight fetal lambs. From 120 to 148 days of gestation the rate of fluid production was 4.5 ml/kg per h, and there was no change in mean fluid sodium (147.8 meq/1), chloride (153.1 meq/1), calcium (2.2 mg/100 ml), and pH (6.23). Tracheal fluid potassium increased from 4.3 meq/1 at 120-130 days to 8.9 meq/1 at term, while plasma sodium, chloride, calcium, pH, and potassium were constant at 146.1 meq/1, 110.0 meq/1, 12.1 mg/100 ml, 7.39, and 4.0 meq/1, respectively. Plasma corticoids were less than 1.5 mug/100 ml total (0.3 mug/100 ml free) until 130 days, when they increased rapidly to 10.5 total (3.2 free) at 148 days. Surfactant was first detected in tracheal fluid between 124 and 133 days and its secretion increased rapidly after 135 days to a value of 125 mug/kg per h at 148 days. A sudden increase in fetal plasma corticoids does not seem to be the stimulus for appearance of surfactant in the lamb, although these hormones may induce the rapid accumulation of surfactant prior to delivery.

This article has been cited by other articles:

				B. Grubor, D. K. Meyerholz, and M. R. Ackermann Collectins and cationic antimicrobial peptides of the respiratory epithelia. Vet. Pathol., September 1, 2006; 43(5): 595 - 612. [Abstract] [Full Text] [PDF]

				W. M. Gilbert Amniotic Fluid Dynamics NeoReviews, June 1, 2006; 7(6): e292 - e299. [Full Text] [PDF]

				L. Nardo, L. Zhao, L. Green, F. Possmayer, B. S. Richardson, and A. D. Bocking The Effect of Repeated Umbilical Cord Occlusions on Pulmonary Surfactant Protein mRNA Levels in the Ovine Fetus Reproductive Sciences, October 1, 2005; 12(7): 510 - 517. [Abstract] [PDF]

				R. D. Bland Lung Fluid Balance During Development NeoReviews, June 1, 2005; 6(6): e255 - e267. [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]

				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]

				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]

				K. A. Wong, A. Bano, A. Rigaux, B. Wang, B. Bharadwaj, S. Schurch, F. Green, J. E. Remmers, and S. U. Hasan Pulmonary vagal innervation is required to establish adequate alveolar ventilation in the newborn lamb J Appl Physiol, September 1, 1998; 85(3): 849 - 859. [Abstract] [Full Text] [PDF]

				J. A. CLEMENTS and M. E. AVERY Lung Surfactant and Neonatal Respiratory Distress Syndrome Am. J. Respir. Crit. Care Med., April 1, 1998; 157(4): S59 - S66. [Full Text] [PDF]

				M. G. Ross and M. J. M. Nijland Development of ingestive behavior Am J Physiol Regulatory Integrative Comp Physiol, April 1, 1998; 274(4): R879 - R893. [Abstract] [Full Text] [PDF]

				O. A. Ogundipe, L. K. Kullama, L. Day, and M. G. Ross Assessments of Fetal Swallowred Volume: Tracer Disappearance Versus Esophageal Flow Reproductive Sciences, January 1, 1994; 1(1): 37 - 44. [Abstract] [PDF]