|
|
||||||||
Journal of Applied Physiology, Vol 63, Issue 2 828-833, Copyright © 1987 by American Physiological Society
ARTICLES |
D. Warburton, L. Parton, S. Buckley, L. Cosico and T. Saluna
Department of Pediatrics, University of Southern California School of Medicine, Children's Hospital of Los Angeles 90027.
We correlated the ontogeny of pulmonary beta-adrenergic receptors with the onset of surface active material (SAM) flux into tracheal fluid of male and female chronically catheterized fetal lambs. SAM flux began between 0.82 and 0.85 gestation in the females and between 0.85 and 0.89 gestation in the males and matured more rapidly thereafter in the females than in the males (P less than 0.01). beta-Adrenergic receptor binding, using [3H]dihydroalprenolol as the ligand, was saturable, linear, and stereospecific. The order of potency of competitive beta-agonists was isoproterenol greater than norepinephrine greater than epinephrine. The maximal binding capacity (Bmax) of pulmonary beta-receptors approximately doubled between 0.84 and 0.89 gestation, coinciding with the onset of SAM flux. Bmax matured as a third degree polynomial function of gestational age in females (r = 0.9, P less than 0.001) but as a linear function in males (r = 0.8, P less than 0.005). Between 0.86 and 0.93 gestation, Bmax was 1.45-fold greater in females than males (P less than 0.001). The dissociation constant of beta-receptors was not influenced significantly by gender or gestation. We conclude that maturation of pulmonary beta-receptors coincides with the onset of SAM flux in fetal lambs and that both mature more rapidly in females. We speculate that pulmonary beta-receptor maturation and SAM flux are coregulated by hormonal factors. More rapid maturation of pulmonary beta-receptors and SAM flux in females may be a factor in the female advantage with regard to pulmonary surfactant maturation and the survival of premature neonates.
This article has been cited by other articles:
![]() |
E. D. Crandall and R. M. Effros Lung Edema Clearance: 20 Years of Progress: Historical perspectives on lung edema clearance J Appl Physiol, October 1, 2002; 93(4): 1527 - 1532. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. D. Bland Loss of liquid from the lung lumen in labor: more than a simple "squeeze" Am J Physiol Lung Cell Mol Physiol, April 1, 2001; 280(4): L602 - L605. [Full Text] [PDF] |
||||
![]() |
X. Jiang, D. H. Ingbar, and S. M. O'Grady Adrenergic stimulation of Na+ transport across alveolar epithelial cells involves activation of apical Cl- channels Am J Physiol Cell Physiol, December 1, 1998; 275(6): C1610 - C1620. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |