Laryngeal reflex apnea in neonates: Effects of CO₂ and the complex influence of hypoxia

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• 作者：L. Xia ; J.C. Leiter ; D. Bartlett Jr. ; ^{donald.bartlett@dartmouth.edu}
• 关键词：Laryngeal chemoreflex ; Sudden Infant Death Syndrome ; Hypocapnia ; Hypercapnia ; Hypoxia ; Piglet
• 刊名：Respiratory Physiology & Neurobiology
• 出版年：2013
• 出版时间：1 March, 2013
• 年：2013
• 卷：186
• 期：1
• 页码：109-113
• 全文大小：339 K

文摘

We have examined influence of hypocapnia, mild hypercapnia and hypoxia on the durations of fictive apnea and respiratory disruption elicited by injection of 0.1 ml of water into the laryngeal lumen¡ªthe laryngeal chemoreflex (LCR)¡ªin 20 unanesthetized, decerebrate, vagotomized piglets aged 4-10 days that were paralyzed and ventilated with a constant frequency and tidal volume. The LCR was enhanced by hypocapnia and attenuated by hypercapnia as reported by others. The responses to laryngeal stimulation during hypoxia were varied and complex: some animals showed abbreviated responses during the tachypnea of early hypoxia, followed after 10-15 min by more prolonged apnea and respiratory disruption accompanying the reduction in ventilatory activity that commonly occurs during sustained hypoxia in neonates. We speculate that this later hypoxic enhancement of the LCR may be due to accumulation of adenosine in the brain stem.