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Nicotine attenuates the ventilatory response to hypoxia in the developing lamb
1Department of Pediatrics, Vanderbilt University, Nashville, Tennessee 37232-2585, USA.
Pediatric Research
|May 1, 1995
Summary
Maternal smoking may increase sudden infant death syndrome (SIDS) risk by impairing infants' breathing responses. Nicotine exposure in lambs reduced their ventilatory response to low oxygen and increased it to high oxygen.
Area of Science:
- Neonatal Physiology
- Respiratory Control
- Toxicology
Background:
- Sudden infant death syndrome (SIDS) is linked to impaired hyperventilatory responses to hypoxemia.
- Maternal smoking is a significant risk factor for SIDS.
- Nicotine's effects on infant respiratory control are not fully understood.
Purpose of the Study:
- To investigate the impact of nicotine on ventilatory responses to hypoxia and hyperoxia in developing lambs.
- To explore potential mechanisms linking maternal smoking, nicotine exposure, and SIDS pathophysiology.
Main Methods:
- Five lambs were studied at 7, 17, and 27 days of age.
- Intravenous nicotine infusion (0.5 microgram/kg/min) was administered.
- Ventilatory responses to hypoxia (0.1 FiO2) and hyperoxia were measured using inspiratory occlusion pressures (P0.1) and minute ventilation.
Main Results:
- Nicotine significantly attenuated the early ventilatory response to hypoxia at 7 and 27 days of age.
- Nicotine exposure led to a greater decrease in ventilation during hyperoxia, particularly at 27 days.
- These paradoxical effects suggest nicotine alters peripheral chemoreceptor sensitivity and central processing.
Conclusions:
- Nicotine exposure appears to impair the normal ventilatory response to hypoxia in developing lambs.
- Nicotine may alter oxygen sensitivity of peripheral chemoreceptors and affect central respiratory control mechanisms.
- Findings suggest a potential mechanism by which maternal smoking could contribute to SIDS risk.