Abstract
The mode of secretion of lung liquid by the pulmonary epithelium of the sheep during late gestation and reabsorption of this liquid around the time of birth has been elucidated, but the role of different regions of the epithelium in these processes has not been examined. We studied bioelectric properties and ion flows across upper airway epithelia excised from fetal sheep and fetal and neonatal dogs. Transepithelial nasal p.d. values of human neonates were also assessed in vivo. The tracheal epithelium of fetal sheep (143 days gestation) secreted Cl- (1.4µEq cm-2 h-1 hour). Na+ movement (1.8 µEq cm-2 h-1) was passive. Transepithelial p.d. (12 mV, lumen negative), short-circuit current (1.6 µEq cm-2 h-1) and Cl- secretion were stimulated by isoproterenol but were not affected by amiloride. Tracheal and 4th to 6th generation bronchial epithelia of maternal sheep absorbed Na+; Cl- movement was passive. Amiloride inhibited p.d., short-circuit current and Na+ transport, but isoproterenol had no effect. Canine fetal and neonatal (up to about 1 month) tracheas exhibited patterns of bioelectric properties, ion flow and drug response similar to those of fetal sheep trachea. Whereas the dominant ion transport deduced from drug responses of canine fetal bronchi resembled those processes of fetal and neonatal trachea, bronchi from 1 month neonates absorbed Na+ and responded to amiloride. Although these results suggest that Na+ absorption by upper airway epithelia matures after birth and proceeds from distal to proximal regions, the transepithelial p.d. values of the nasal turbinate of term and preterm infants were close to the mature value (-30 mV, lumen negative) at birth. Moreover, amiloride induced a similar inhibition of p.d. (40%) of turbinates of infants and adults. This departure from the pattern predicted from the canine studies could reflect species and/or regional differences in airway epithelial function.
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Olver, R. E. and Strang, L. B. (1974). Ion fluxes across the pulmonary epithelium and the secretion of lung liquid in the fetal lamb. J. Physiol. (Lond.), 241, 327–57
Walters, D. V. and Olver, R. E. (1978). The role of catecholamines in lung liquid absorption at birth. Pediatr. Res., 12, 239–42
Olver, R. E. (1983). Fluid balance across the fetal alveolar epithelium. Am. Rev. Respir. Dis., 127, 533–6
Bland, R. D., Braun, D. and Boyd, C. A. R. (1985). Labor stimulates Na-K-ATPase activity in lung epithelial cells of fetal rabbits. Fed. Proc., 44, 640
McAteer, J. A., Cavanaugh, T. J. and Evan, A. P. (1983). Submersion culture of the intact fetal lung. In Vitro, 19, 210–18
Kilburn, K. H. (1968). A hypothesis for pulmonary clearance and its implications. Am. Rev. Respir. Dis., 98, 449–63
Cotton, C. U., Lawson, E. E., Boucher, R. C. and Gatzy, J. T. (1983). Bioelectric properties and ion transport of airways excised from adult and fetal sheep. J. Appl. Physiol.: Respir at. Environ. Exercise Physiol., 55, 1542–9
Boucher, R. C., Stutts, M. J. and Gatzy, J. T. (1981). Regional differences in bioelectric properties and ion flow in excised canine airways. J. Appl. Physiol.: Respirat. Environ. Exercise Physiol., 51, 706–19
Cotton, C. U., Boucher, R. C. and Gatzy, J. T. (1984). Bioelectric properties and ion flows across excised fetal and neonatal dog trachea. Fed. Proc., 43, 830
Knowles, M. R., Carson, J. L., Collier, A. M., Gatzy, J. T. and Boucher, R. C. (1981). Measurements of transepithelial electric potential differences in the trachea and bronchi of human subjects in vivo. Am. Rev. Respir. Dis., 124, 484–90
Knowles, M. R., Stutts, M. J., Spock, A., Fischer, N., Gatzy, J. T. and Boucher, R. C. (1983). Abnormal ion permeation through cystic fibrosis respiratory epithelium. Science, 221, 1067–70
Knowles, M. R., Gowen, C. W. Jr., Lawson, E. E., Gatzy, J. T. and Boucher, R. C. (1985). Nasal potential difference and amiloride sensitivity in neonates with cystic fibro-sis. C. F. Club Abstracts, 26, 7
Boucher, R. C., Stutts, M. J., Knowles, M. R., Cantley, L. and Gatzy, J. T. (1985). Na+ transport in cystic fibrosis nasal epithelia: abnormal basal rate and response to adenylate cyclase activation. Clin. Res., 33, 467A
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1987 MTP Press Limited
About this chapter
Cite this chapter
Gatzy, J.T., Cotton, C.U., Boucher, R.C., Knowles, M.R., Gowen, C.W. (1987). Development of Epithelial Ion Transport in Fetal and Neonatal Airways. In: Walters, D.V., Strang, L.B., Geubelle, F. (eds) Physiology of the Fetal and Neonatal Lung. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-4155-7_6
Download citation
DOI: https://doi.org/10.1007/978-94-009-4155-7_6
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-010-8344-7
Online ISBN: 978-94-009-4155-7
eBook Packages: Springer Book Archive