Journal of Applied Physiology, Vol 70, Issue 3 1146-1151, Copyright © 1991 by American Physiological Society

ARTICLES

Ventilation in newborn rats after gestation at simulated high altitude

R. D. Gleed and J. P. Mortola
Department of Physiology, McGill University, Montreal, Quebec, Canada.

Pregnant rats were kept at a simulated altitude of 4,500 m (PO2 91 Torr) for the whole of gestation and returned to sea level 1 day after giving birth. During pregnancy, body weight gain and food intake were approximately 30% less than in controls at sea level. Measurements were made on the 1-day-old (HYPO) pups after a few hours at sea level. In normoxia, ventilation (VE) measured by flow plethysmography was more (+17%) and O2 consumption (VO2) measured by a manometric method was less (-19%) than in control (CONT) pups; in HYPO pups VE/VO2 was 44% greater than in CONT pups. In acute hyperoxia, VE/VO2 of HYPO and CONT pups decreased by a similar amount (15-20%), indicating some limitation in O2 availability for both groups of pups in normoxia. However, VE/VO2 of HYPO pups, even in hyperoxia, remained above (+34%) that of CONT pups. HYPO pups weighed slightly less than CONT pups, their lungs were hypoplastic, and their hearts were a larger fraction of body weight. An additional group of female rats was acclimatized (8 days) to high altitude before insemination. During pregnancy, body weight gain and food intake of these females were similar to those of pregnant rats at sea level. Measurements on the 1-day-old pups of this group were similar to those of HYPO pups. We conclude that newborn rats born after hypoxic gestation present metabolic adaptation (low VO2) and acclimatization (high VE/VO2), possibly because of hypoxemia. Maternal acclimatization before insemination substantially alters maternal growth in hypoxia but does not affect neonatal outcome.

This article has been cited by other articles:

				R. W. Bavis and G. S. Mitchell Long-term effects of the perinatal environment on respiratory control J Appl Physiol, April 1, 2008; 104(4): 1220 - 1229. [Abstract] [Full Text] [PDF]

				C. Dubois, H. Houchi, M. Naassila, M. Daoust, and O. Pierrefiche Blunted response to low oxygen of rat respiratory network after perinatal ethanol exposure: involvement of inhibitory control J. Physiol., March 1, 2008; 586(5): 1413 - 1427. [Abstract] [Full Text] [PDF]

				K. Szdzuy and J. P. Mortola Ventilatory chemosensitivity of the 1-day-old chicken hatchling after embryonic hypoxia Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2007; 293(4): R1640 - R1649. [Abstract] [Full Text] [PDF]

				M. A. Azzam, K. Szdzuy, and J. P. Mortola Hypoxic incubation blunts the development of thermogenesis in chicken embryos and hatchlings Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2007; 292(6): R2373 - R2379. [Abstract] [Full Text] [PDF]

				Y. Xu, S. J. Williams, D. O'Brien, and S. T. Davidge Hypoxia or nutrient restriction during pregnancy in rats leads to progressive cardiac remodeling and impairs postischemic recovery in adult male offspring FASEB J, June 1, 2006; 20(8): 1251 - 1253. [Abstract] [Full Text] [PDF]

				S. J. Williams, D. G. Hemmings, J. M. Mitchell, I. C. McMillen, and S. T. Davidge Effects of maternal hypoxia or nutrient restriction during pregnancy on endothelial function in adult male rat offspring J. Physiol., May 15, 2005; 565(1): 125 - 135. [Abstract] [Full Text] [PDF]

				S. J. Williams, M. E. Campbell, I. C. McMillen, and S. T. Davidge Differential effects of maternal hypoxia or nutrient restriction on carotid and femoral vascular function in neonatal rats Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2005; 288(2): R360 - R367. [Abstract] [Full Text] [PDF]

				D. Gozal, S. R. Reeves, B. W. Row, J. J. Neville, S. Z. Guo, and A. J. Lipton Respiratory Effects of Gestational Intermittent Hypoxia in the Developing Rat Am. J. Respir. Crit. Care Med., June 1, 2003; 167(11): 1540 - 1547. [Abstract] [Full Text] [PDF]

				J. L. Carroll Plasticity in Respiratory Motor Control: Invited Review: Developmental plasticity in respiratory control J Appl Physiol, January 1, 2003; 94(1): 375 - 389. [Abstract] [Full Text] [PDF]

				A. Okumura, F. Hayakawa, T. Kato, K. Itomi, K. Maruyama, N. Ishihara, T. Kubota, M. Suzuki, Y. Sato, K. Kuno, et al. Hypocarbia in Preterm Infants With Periventricular Leukomalacia: The Relation Between Hypocarbia and Mechanical Ventilation Pediatrics, March 1, 2001; 107(3): 469 - 475. [Abstract] [Full Text]

				J. P. Mortola and E. L. Seifert Hypoxic depression of circadian rhythms in adult rats J Appl Physiol, February 1, 2000; 88(2): 365 - 368. [Abstract] [Full Text] [PDF]

				J. P. Mortola and L. Naso Thermogenesis in newborn rats after prenatal or postnatal hypoxia J Appl Physiol, July 1, 1998; 85(1): 84 - 90. [Abstract] [Full Text] [PDF]