|
|
||||||||
Department of Physiology and Biophysics, University of Calgary Health Sciences Centre, Calgary, Alberta T2N 4N1, Canada
Failure to autoresuscitate from apnea by gasping has been suggested to have a role in sudden infant death. Little is known, however, about the factors that influence the ability of gasping to sustain life during acute hypoxia in the newborn. The present experiments were carried out on 105 rat pups to investigate the influence of postnatal age on the time to last gasp during a single hypoxic exposure and on the ability to autoresuscitate from primary apnea during repeated hypoxic exposures. On days 1-2, 5-6, 10-11, 15-16, and 19-20 postpartum, each pup was placed into a temperature-controlled chamber regulated to 37 ± 1°C and was exposed either to a single period of hypoxia produced by breathing an anoxic gas mixture (97% N2-3% CO2), and the time to last gasp was determined, or repeated exposure to hypoxia was performed, and the ability to autoresuscitate from primary apnea was determined. Increases in postnatal age decreased the time to last gasp following a single hypoxic exposure and decreased the number of successful autoresuscitations following repeated hypoxic exposures. Thus our data provide evidence that postnatal age influences protective responses that may prevent death during hypoxia as may occur during episodes of prolonged sleep apnea.
autoresuscitation; hypoxia; sudden infant death syndrome
This article has been cited by other articles:
![]() |
B. T. Thach Some aspects of clinical relevance in the maturation of respiratory control in infants J Appl Physiol, June 1, 2008; 104(6): 1828 - 1834. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Taccola, L. Secchia, and K. Ballanyi Anoxic persistence of lumbar respiratory bursts and block of lumbar locomotion in newborn rat brainstem spinal cords J. Physiol., December 1, 2007; 585(2): 507 - 524. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Marchenko and R. F. Rogers Temperature and state dependence of dynamic phrenic oscillations in the decerebrate juvenile rat Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2007; 293(6): R2323 - R2335. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Fewell, C. Zhang, and A. M. Gillis Influence of adenosine A1-receptor blockade and vagotomy on the gasping and heart rate response to hypoxia in rats during early postnatal maturation J Appl Physiol, October 1, 2007; 103(4): 1234 - 1241. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Marchenko and R. F. Rogers Selective loss of high-frequency oscillations in phrenic and hypoglossal activity in the decerebrate rat during gasping Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2006; 291(5): R1414 - R1429. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Marchenko and R. F. Rogers Time-frequency coherence analysis of phrenic and hypoglossal activity in the decerebrate rat during eupnea, hyperpnea, and gasping Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2006; 291(5): R1430 - R1442. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Fewell, V. K. Y. Ng, and C. Zhang Prior exposure to hypoxic-induced apnea impairs protective responses of newborn rats in an exposure-dependent fashion: influence of normoxic recovery time J Appl Physiol, October 1, 2005; 99(4): 1607 - 1612. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Luo, S. Costy-Bennett, and R. F Fregosi Prenatal nicotine exposure increases the strength of GABAA receptor-mediated inhibition of respiratory rhythm in neonatal rats J. Physiol., December 1, 2004; 561(2): 387 - 393. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Gozal, E. Gozal, S. R. Reeves, and A. J. Lipton Gasping and autoresuscitation in the developing rat: effect of antecedent intermittent hypoxia J Appl Physiol, March 1, 2002; 92(3): 1141 - 1144. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Fewell, F. G. Smith, and V. K. Y. Ng Threshold levels of maternal nicotine impairing protective responses of newborn rats to intermittent hypoxia J Appl Physiol, May 1, 2001; 90(5): 1968 - 1976. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |