Lung function in developing lambs: is it affected by preterm birth?
Open Access
- 1 October 2009
- journal article
- research article
- Published by American Physiological Society in Journal of Applied Physiology
- Vol. 107 (4), 1083-1088
- https://doi.org/10.1152/japplphysiol.00129.2009
Abstract
Children born before term often have reduced lung function, but the effects of preterm birth alone are difficult to determine owing to iatrogenic factors such as mechanical ventilation. Our objective was to determine the effects of preterm birth alone on airway resistance, airway reactivity, and ventilatory heterogeneity as an index of intrapulmonary gas mixing. Preterm birth was induced in sheep 12 days before term; controls were born at term (∼147 days). Lung function was assessed at 8 wk postterm. To assess medium-large airway function we measured airway resistance and reactivity to carbachol. Multiple breath N2 washout (MBW) was used to assess ventilatory heterogeneity in conducting (Scond) and acinar (Sacin) airways. Baseline airway resistance and responsiveness to carbachol were similar in preterm and term lambs. Airway responsiveness to carbachol was greater in females than males ( P < 0.05), and baseline airway resistance tended to be higher in females than males ( P = 0.06). There were no significant differences in ventilatory heterogeneity between preterm and term lambs; for all animals combined, mean Sacin was 0.29 ± 0.05 liter−1 and Scond was 0.26 ± 0.03 liter−1. Males had significantly higher Scond than females, indicating poorer gas mixing in small conducting airways; there was no sex difference in Sacin. We conclude that preterm birth per se in lambs does not affect baseline airway resistance, airway responsiveness, or ventilatory heterogeneity as measured by MBW. The observed sex-related differences in airway responsiveness and ventilatory heterogeneity in the conducting airways could help explain sex differences in lung function observed in humans.This publication has 30 references indexed in Scilit:
- Long-Term Pulmonary Outcome in the Preterm InfantNeonatology, 2008
- POSTNATAL GROWTH RATE, BUT NOT MILD PRETERM BIRTH, INFLUENCES AIRWAY STRUCTURE IN ADULT SHEEP CHALLENGED WITH HOUSE DUST MITEExperimental Lung Research, 2008
- ALTERED AIRWAY RESPONSIVENESS IN ADULT SHEEP BORN PREMATURELY: EFFECTS OF ALLERGEN EXPOSUREExperimental Lung Research, 2006
- Respiratory function of very prematurely born infants at follow up: influence of sexArchives of Disease in Childhood: Fetal & Neonatal, 2005
- Effects of methacholine on small airway function measured by forced oscillation technique and multiple breath nitrogen washout in normal subjectsRespiratory Physiology & Neurobiology, 2005
- Pulmonary function and structure following mild preterm birth in lambsPediatric Pulmonology, 2005
- Risk factors for respiratory morbidity in infancy after very premature birthArchives of Disease in Childhood: Fetal & Neonatal, 2005
- Neonatal respiratory mechanics and development of bronchial hyperresponsiveness in preterm infantsEarly Human Development, 2004
- Respiratory morbidity in preschool children born prematurely. Relationship to adverse neonatal eventsActa Paediatrica, 1996
- Postnatal human lung growth.Thorax, 1982