Journal of Applied Physiology, Vol 77, Issue 2 782-788, Copyright © 1994 by American Physiological Society

ARTICLES

Lung vascular protein permeability in preterm fetal and mature newborn sheep

D. P. Carlton, J. J. Cummings, R. G. Scheerer and R. D. Bland
Cardiovascular Research Institute, University of California, San Francisco 94143.

The purpose of this study was to see whether there are developmental differences in the protein permeability of the pulmonary circulation that might contribute to the abnormal lung fluid balance seen in premature lambs with respiratory failure. In one series of experiments, we measured albumin turnover time, which reflects the escape rate of radiolabeled albumin from the pulmonary circulation, of five preterm fetal lambs (125 +/- 1 days gestation) and five newborn lambs (19 +/- 9 days old). Turnover time was not significantly different in fetuses (160 +/- 38 min) and newborns (141 +/- 54 min), implying a similar protein permeability of the pulmonary circulation. In additional experiments, we measured pulmonary hemodynamic and lung lymph flow responses to intravenous saline infusion in seven preterm fetal lambs (130 +/- 3 days gestation) and seven newborn lambs (14 +/- 3 days old). During saline infusion, calculated fluid filtration pressure increased by a similar amount in fetuses and newborns (3.4 +/- 0.8 and 2.8 +/- 0.9 Torr, respectively), resulting in a similar change in lung lymph flow in fetuses and newborns (0.59 +/- 0.27 and 0.55 +/- 0.25 ml.h-1.kg body wt-1, respectively). The results of these studies indicate that protein permeability of the pulmonary circulation does not change significantly during late fetal and early postnatal development.

This article has been cited by other articles:

				D. P. Carlton, K. H. Albertine, S. C. Cho, M. Lont, and R. D. Bland Role of neutrophils in lung vascular injury and edema after premature birth in lambs J Appl Physiol, October 1, 1997; 83(4): 1307 - 1317. [Abstract] [Full Text] [PDF]