Increased sodium absorption across the nasal epithelium of ventilated moderately preterm infants on the first day of postnatal life

E. Gaillard, N. Shaw, H. Wallace, N. Subhedar, K. Southern

Research output: Contribution to conferencePaper

Abstract

Aims: To examine through the nasal potential difference (PD) profile, airway ion transport in moderately preterm infants (from 29 weeks gestation). Background: Despite recent advances, lung disease following premature birth remains a significant clinical problem. Animal and clinical studies suggest that airway ion transport has a critical role in the adaptation to air breathing in postnatal life. In particular, sodium absorption mediated through the epithelial sodium channel (ENaC) is a major factor in lung water clearance after birth.(1) The a-ENaC subunit m-RNA expression has been found to increase with gestational age.(2) Immature airway ion transport as a result of prematurity may therefore contribute to the respiratory morbidity in infants born moderately preterm. Methods: We studied 75 infants using a modified perfusion protocol suitable for neonates (healthy term infants n = 40; preterm 29-36 weeks gestation n = 35). We determined: 1.) Maximal baseline PD following perfusion of a physiological isotonic solution 2.) The change in PD following perfusion with amiloride 10-4 M (?amil, to assess ENaC activity) 3.) The change in PD, after perfusion with a solution low in Cl- (to assess the capacity for Cl- secretion). Results: Maximal baseline PDs are shown in graph 1. Four ventilated infants had maximal baseline PDs greater than -50mV. Amiloride perfusion resulted in substantial reduction in PD magnitude (median ?amil in pretem, 80%) and there was little capacity for chloride secretion in either cohort. □: ventilated male infants; ■: non-ventilated male infants ∆: ventilated female infants; ▲: non-ventilated female infants Conclusion: This is the first reported clinical study examining the postnatal airway ion transport pattern in moderately preterm infants and these data suggest these processes are well developed in these infants on day 1 of postnatal life. The findings support a normal switch from the fetal secretory pattern to a fluid absorptive state after birth in this cohort, similar to term infants. We found increased nasal PD in some ventilated preterm infants after birth. ?amil in these infants confirms that the increased PD principally reflects ENaC-mediated sodium absorption. The sodium hyperabsorption evident in some of the ventilated preterm infants may reflect a compensatory mechanism to clear fluid from the lungs.
Original languageEnglish
Publication statusPublished - 2002
EventEuropean Society for Paediatric Research Annual Meeting - Utrecht, Netherlands
Duration: 25 Dec 2002 → …

Conference

ConferenceEuropean Society for Paediatric Research Annual Meeting
CountryNetherlands
CityUtrecht
Period25/12/02 → …

Fingerprint

Nasal Mucosa
Premature Infants
Sodium
Ion Transport
Perfusion
Amiloride
Parturition
Nose
Epithelial Sodium Channels
Pregnancy
Lung
Premature Birth
Lung Diseases
Gestational Age
Chlorides
Respiration
Air
Newborn Infant
RNA
Morbidity

Cite this

Gaillard, E., Shaw, N., Wallace, H., Subhedar, N., & Southern, K. (2002). Increased sodium absorption across the nasal epithelium of ventilated moderately preterm infants on the first day of postnatal life. Paper presented at European Society for Paediatric Research Annual Meeting, Utrecht, Netherlands.
Gaillard, E. ; Shaw, N. ; Wallace, H. ; Subhedar, N. ; Southern, K. / Increased sodium absorption across the nasal epithelium of ventilated moderately preterm infants on the first day of postnatal life. Paper presented at European Society for Paediatric Research Annual Meeting, Utrecht, Netherlands.
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title = "Increased sodium absorption across the nasal epithelium of ventilated moderately preterm infants on the first day of postnatal life",
abstract = "Aims: To examine through the nasal potential difference (PD) profile, airway ion transport in moderately preterm infants (from 29 weeks gestation). Background: Despite recent advances, lung disease following premature birth remains a significant clinical problem. Animal and clinical studies suggest that airway ion transport has a critical role in the adaptation to air breathing in postnatal life. In particular, sodium absorption mediated through the epithelial sodium channel (ENaC) is a major factor in lung water clearance after birth.(1) The a-ENaC subunit m-RNA expression has been found to increase with gestational age.(2) Immature airway ion transport as a result of prematurity may therefore contribute to the respiratory morbidity in infants born moderately preterm. Methods: We studied 75 infants using a modified perfusion protocol suitable for neonates (healthy term infants n = 40; preterm 29-36 weeks gestation n = 35). We determined: 1.) Maximal baseline PD following perfusion of a physiological isotonic solution 2.) The change in PD following perfusion with amiloride 10-4 M (?amil, to assess ENaC activity) 3.) The change in PD, after perfusion with a solution low in Cl- (to assess the capacity for Cl- secretion). Results: Maximal baseline PDs are shown in graph 1. Four ventilated infants had maximal baseline PDs greater than -50mV. Amiloride perfusion resulted in substantial reduction in PD magnitude (median ?amil in pretem, 80{\%}) and there was little capacity for chloride secretion in either cohort. □: ventilated male infants; ■: non-ventilated male infants ∆: ventilated female infants; ▲: non-ventilated female infants Conclusion: This is the first reported clinical study examining the postnatal airway ion transport pattern in moderately preterm infants and these data suggest these processes are well developed in these infants on day 1 of postnatal life. The findings support a normal switch from the fetal secretory pattern to a fluid absorptive state after birth in this cohort, similar to term infants. We found increased nasal PD in some ventilated preterm infants after birth. ?amil in these infants confirms that the increased PD principally reflects ENaC-mediated sodium absorption. The sodium hyperabsorption evident in some of the ventilated preterm infants may reflect a compensatory mechanism to clear fluid from the lungs.",
author = "E. Gaillard and N. Shaw and H. Wallace and N. Subhedar and K. Southern",
year = "2002",
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Gaillard, E, Shaw, N, Wallace, H, Subhedar, N & Southern, K 2002, 'Increased sodium absorption across the nasal epithelium of ventilated moderately preterm infants on the first day of postnatal life' Paper presented at European Society for Paediatric Research Annual Meeting, Utrecht, Netherlands, 25/12/02, .

Increased sodium absorption across the nasal epithelium of ventilated moderately preterm infants on the first day of postnatal life. / Gaillard, E.; Shaw, N.; Wallace, H.; Subhedar, N.; Southern, K.

2002. Paper presented at European Society for Paediatric Research Annual Meeting, Utrecht, Netherlands.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Increased sodium absorption across the nasal epithelium of ventilated moderately preterm infants on the first day of postnatal life

AU - Gaillard, E.

AU - Shaw, N.

AU - Wallace, H.

AU - Subhedar, N.

AU - Southern, K.

PY - 2002

Y1 - 2002

N2 - Aims: To examine through the nasal potential difference (PD) profile, airway ion transport in moderately preterm infants (from 29 weeks gestation). Background: Despite recent advances, lung disease following premature birth remains a significant clinical problem. Animal and clinical studies suggest that airway ion transport has a critical role in the adaptation to air breathing in postnatal life. In particular, sodium absorption mediated through the epithelial sodium channel (ENaC) is a major factor in lung water clearance after birth.(1) The a-ENaC subunit m-RNA expression has been found to increase with gestational age.(2) Immature airway ion transport as a result of prematurity may therefore contribute to the respiratory morbidity in infants born moderately preterm. Methods: We studied 75 infants using a modified perfusion protocol suitable for neonates (healthy term infants n = 40; preterm 29-36 weeks gestation n = 35). We determined: 1.) Maximal baseline PD following perfusion of a physiological isotonic solution 2.) The change in PD following perfusion with amiloride 10-4 M (?amil, to assess ENaC activity) 3.) The change in PD, after perfusion with a solution low in Cl- (to assess the capacity for Cl- secretion). Results: Maximal baseline PDs are shown in graph 1. Four ventilated infants had maximal baseline PDs greater than -50mV. Amiloride perfusion resulted in substantial reduction in PD magnitude (median ?amil in pretem, 80%) and there was little capacity for chloride secretion in either cohort. □: ventilated male infants; ■: non-ventilated male infants ∆: ventilated female infants; ▲: non-ventilated female infants Conclusion: This is the first reported clinical study examining the postnatal airway ion transport pattern in moderately preterm infants and these data suggest these processes are well developed in these infants on day 1 of postnatal life. The findings support a normal switch from the fetal secretory pattern to a fluid absorptive state after birth in this cohort, similar to term infants. We found increased nasal PD in some ventilated preterm infants after birth. ?amil in these infants confirms that the increased PD principally reflects ENaC-mediated sodium absorption. The sodium hyperabsorption evident in some of the ventilated preterm infants may reflect a compensatory mechanism to clear fluid from the lungs.

AB - Aims: To examine through the nasal potential difference (PD) profile, airway ion transport in moderately preterm infants (from 29 weeks gestation). Background: Despite recent advances, lung disease following premature birth remains a significant clinical problem. Animal and clinical studies suggest that airway ion transport has a critical role in the adaptation to air breathing in postnatal life. In particular, sodium absorption mediated through the epithelial sodium channel (ENaC) is a major factor in lung water clearance after birth.(1) The a-ENaC subunit m-RNA expression has been found to increase with gestational age.(2) Immature airway ion transport as a result of prematurity may therefore contribute to the respiratory morbidity in infants born moderately preterm. Methods: We studied 75 infants using a modified perfusion protocol suitable for neonates (healthy term infants n = 40; preterm 29-36 weeks gestation n = 35). We determined: 1.) Maximal baseline PD following perfusion of a physiological isotonic solution 2.) The change in PD following perfusion with amiloride 10-4 M (?amil, to assess ENaC activity) 3.) The change in PD, after perfusion with a solution low in Cl- (to assess the capacity for Cl- secretion). Results: Maximal baseline PDs are shown in graph 1. Four ventilated infants had maximal baseline PDs greater than -50mV. Amiloride perfusion resulted in substantial reduction in PD magnitude (median ?amil in pretem, 80%) and there was little capacity for chloride secretion in either cohort. □: ventilated male infants; ■: non-ventilated male infants ∆: ventilated female infants; ▲: non-ventilated female infants Conclusion: This is the first reported clinical study examining the postnatal airway ion transport pattern in moderately preterm infants and these data suggest these processes are well developed in these infants on day 1 of postnatal life. The findings support a normal switch from the fetal secretory pattern to a fluid absorptive state after birth in this cohort, similar to term infants. We found increased nasal PD in some ventilated preterm infants after birth. ?amil in these infants confirms that the increased PD principally reflects ENaC-mediated sodium absorption. The sodium hyperabsorption evident in some of the ventilated preterm infants may reflect a compensatory mechanism to clear fluid from the lungs.

M3 - Paper

ER -

Gaillard E, Shaw N, Wallace H, Subhedar N, Southern K. Increased sodium absorption across the nasal epithelium of ventilated moderately preterm infants on the first day of postnatal life. 2002. Paper presented at European Society for Paediatric Research Annual Meeting, Utrecht, Netherlands.