Selecting representative ages for developmental changes of respiratory irregularities and hypoxic ventilatory response in rats
Lalah M. Niane, Aida Bairam
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DOI: 10.4236/ojmip.2011.11001   PDF    HTML     5,031 Downloads   11,487 Views   Citations

Abstract

Apnea frequency and the weak ventilatory response to hypoxia are a major clinical correlates of the immaturity of respiratory control system in preterm neonates. Rats are frequently used as model to study the respiratory control during development. However, little is known about the postnatal ages that best represent these respiratory irregularities and the hypoxic ventilatory response. Using plethysmography, we assessed baseline minute ventilation, ventilatory response to moderate hypoxia (FiO2 = 12%, 20 min) and apnea frequency in awake and non-anesthetized rats at the postnatal ages of 1, 4, 7, 12, 21 and 90 days old (P1, P4, P7, P12, P21, and P90, respectively). Baseline minute ventilation slightly increased in P4 (~25% vs P1) then gradually decreased with age (age effect: p < 0.05). The lowest level of ventilation was observed in P90 (p < 0.01 vs all ages). Minute ventilation (% from baseline) in response to hypoxia showed the well-known biphasic pattern in all rats at 12 days old or less. Minute ventilation at the initial phase of the hypoxic response was not significantly different between P1, P4, between P7, P12 and between P21, P90. The late phase of the hypoxic response was similar between P1, P4, and between P21, P90, but was significantly different between P7 and P12 (p < 0.05). Under baseline or hypoxic condition, the higher number of apnea frequency (spontaneous and post- sigh) was observed in P1, it then decreased progressively with age (age effect: p < 0.01 for baseline; p < 0.001 for hypoxia). These results suggest that when P4, P7 and P12 are selected to represent the age-dependent changes of the hypoxic ventilatory response in rats, the P1 rats should be included to better describe the age-dependence of apnea frequency.

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Niane, L. and Bairam, A. (2011) Selecting representative ages for developmental changes of respiratory irregularities and hypoxic ventilatory response in rats. Open Journal of Molecular and Integrative Physiology, 1, 1-7. doi: 10.4236/ojmip.2011.11001.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] Bissonnette, J.M. (2000) Mechanisms regulating hypoxic respiratory depression during fetal and postnatal life. American Journal of Physiology Regulatory, Integrative and Comparative Physiology, 278, R 1391-1400.
[2] Carroll, J.L. (2003) Developmental plasticity in respiratory control. Journal of Applied Physiology, 94, 375-389.
[3] Cohen, G. and Katz-Salamon, M. (2005) Development of chemoreceptor responses in infants. Respiratory Physiology & Neurobiology, 149, 233-242. doi:10.1016/j.resp.2005.02.013
[4] Eden, G.J. and Hanson, M.A. (1987) Maturation of the respiratory response to acute hypoxia in the newborn rat. Journal of Physiology, 392, 1-9.
[5] Liu, Q., Lowry, T.F. and Wong-Riley, M.T. (2006) Postnatal changes in ventilation during normoxia and acute hypoxia in the rat: implication for a sensitive period. Journal of Physiology, 577, 957-970. doi:10.1113/jphysiol.2006.121970
[6] Romijn, H.J., Hofman, M.A. and Gramsbergen, A. (1991) At what age is the developing cerebral cortex of the rat comparable to that of the full-term newborn human baby? Early Human Development, 26, 61-67. doi:10.1016/0378-3782(91)90044-4
[7] Behan, M. and Wenninger, J.M. (2008) Sex steroidal hormones and respiratory control. Respiratory Physiology & Neurobiology, 164, 213-221. doi:10.1016/j.resp.2008.06.006
[8] Julien, C., Bairam, A. and Joseph, V. (2008) Chronic intermittent hypoxia reduces ventilatory long-term facilitation and enhances apnea frequency in newborn rats. American Journal of Physiology Regulatory, Integrative and Comparative Physiology, 294, R1356-1366. doi:10.1152/ajpregu.00884.2007
[9] Niane, L.M., Donnelly, D.F., Joseph, V. and Bairam, A. (2010) Ventilatory and carotid body chemoreceptor responses to purinergic P2X receptor antagonists in newborn rats. Journal of Applied Physiology, 110, 83-94. doi:10.1152/japplphysiol.00871.2010
[10] Julien, C.A., Niane, L., Kinkead, R., Bairam, A. and Joseph, V. (2010) Carotid sinus nerve stimulation, but not intermittent hypoxia, induces respiratory LTF in adult rats exposed to neonatal intermittent hypoxia. American Journal of Physiology Regulatory, Integrative and Comparative Physiology, 299, R192-205. doi:10.1152/ajpregu.00707.2009
[11] Bartlett, D.Jr. and Tenney, S.M. (1970) Control of breathing in experimental anemia. Respiratory Physiology, 10, 384-395. doi:10.1016/0034-5687(70)90056-3
[12] Montandon, G., Bairam, A. and Kinkead, R. (2006) Long-term consequences of neonatal caffeine on ventilation, occurrence of apneas, and hypercapnic chemoreflex in male and female rats. Pediatric Research, 59, 519-524. doi:10.1203/01.pdr.0000203105.63246.8a
[13] Mendelson, W.B., Martin, J.V., Perlis, M., Giesen, H., Wagner, R. and Rapoport, S.I. (1988) Periodic cessation of respiratory effort during sleep in adult rats. Physiology & Behavior, 43, 229-234. doi:10.1016/0031-9384(88)90243-0
[14] Julien, C.A., Joseph, V. and Bairam, A. (2010) Caffeine reduces apnea frequency and enhances ventilatory long-term facilitation in rat pups raised in chronic intermittent hypoxia. Pediatric Research, 68, 105-111. doi:10.1203/PDR.0b013e3181e5bc78
[15] Parmeggiani, P.L. (1985) Regulation of circulation and breathing during sleep: experimental aspects. Annals of Clinical Research, 17, 185-189.
[16] Putnam, R.W., Conrad, S.C., Gdovin, M.J., Erlichman, J.S. and Leiter, J.C. (2005) Neonatal maturation of the hypercapnic ventilatory response and central neural CO2 chemosensitivity. Respiratory Physiology & Neurobiology, 149, 165-179. doi:10.1016/j.resp.2005.03.004
[17] Darnall, R.A., Ariagno, R.L. and Kinney, H.C. (2006) The late preterm infant and the control of breathing, sleep, and brainstem development: a review. Clinics in Perinatology, 33, 883-914. doi:10.1016/j.clp.2006.10.004
[18] Gulemetova, R. and Kinkead, R. (2011) Neonatal stress increases respiratory instability in rat pups. Respiratory Physiology & Neurobiology, in press. doi:10.1016/j.resp.2011.01.014
[19] Mateika, J.H. and Narwani, G. (2009) Intermittent hypoxia and respiratory plasticity in humans and other animals: does exposure to intermittent hypoxia promote or mitigate sleep apnoea? Experimental Physiology, 94, 279-296. doi:10.1113/expphysiol.2008.045153
[20] Bavis, R.W. and Mitchell, G.S. (2008) Long-term effects of the perinatal environment on respiratory control. Journal of Applied Physiology, 104, 1220-1229. doi:10.1152/japplphysiol.01086.2007
[21] Montandon, G., Bairam, A. and Kinkead, R. (2008) Neonatal caffeine induces sex-specific developmental plasticity of the hypoxic respiratory chemoreflex in adult rats, American Journal of Physiology Regulatory, Integrative and Comparative Physiology, 295, R922-934. doi:10.1152/ajpregu.00059.2008
[22] Enhorning, G., Schaik, van S., Lundgren, C. and Vargas, I. (1998) Whole-body plethysmography, does it measure tidal volume of small animals? Canadian Journal of Physiology and Pharmacology, 76, 945-951. doi:10.1139/y99-002
[23] Mortola, J.P. and Frappell, P.B. (1998) On the barometric method for measurements of ventilation, and its use in small animals. Canadian Journal of Physiology and Pharmacology, 76, 937-944. doi:10.1139/y99-001
[24] Blumberg, M.S., Seelke, A.M., Lowen, S.B. and Karlsson, K.A. (2005) Dynamics of sleep-wake cyclicity in developing rats. Proceedings of the National Academy of Sciences, USA, 102, 14860-14864. doi:10.1073/pnas.0506340102
[25] Frank, M.G. and Heller, H.C. (1997) Development of REM and slow wave sleep in the rat. American Journal of Physiology, 272, R1792-1799.

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