Skip to main content
NCBI home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1980 May;302:19–29. doi: 10.1113/jphysiol.1980.sp013227

Breathing movements in fetal lambs and the effect of hypercapnia.

R L Chapman, G S Dawes, D W Rurak, P L Wilds
PMCID: PMC1282832  PMID: 6774085

Abstract

1. A breath-by-breath analysis was made of tracheal pressure records from fetal lambs in utero at 117--130 days gestation. 2. Episodes of rapid irregular breathing were accompanied by diaphragmatic e.m.g. activity and were characterized by a gradual increase in breathing rate initially and a terminal decline. Within each episode breathing was very irregular. 3. Inspiratory time increased with increasing expiratory time rapidly as the rate fell to about 80/min, and thereafter more slowly. 4. The principal effects of hypercapnia (a rise in fetal Pa, CO2 by approximately 11 mmHg) were to increase the depth of fetal breathing, by nearly twofold, and to make breathing much more regular. A change in rate was doubtful because of the skew distribution of normal breath intervals.

Full text

PDF
19

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Boddy K., Dawes G. S., Fisher R., Pinter S., Robinson J. S. Foetal respiratory movements, electrocortical and cardiovascular responses to hypoxaemia and hypercapnia in sheep. J Physiol. 1974 Dec;243(3):599–618. doi: 10.1113/jphysiol.1974.sp010768. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Chapman R. L., Dawes G. S., Rurak D. W., Wilds P. L. Intermittent breathing before death in fetal lambs. Am J Obstet Gynecol. 1978 Aug 15;131(8):894–898. doi: 10.1016/s0002-9378(16)33138-6. [DOI] [PubMed] [Google Scholar]
  3. Clark F. J., von Euler C. On the regulation of depth and rate of breathing. J Physiol. 1972 Apr;222(2):267–295. doi: 10.1113/jphysiol.1972.sp009797. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Dalton K. J., Dawes G. S., Patrick J. E. Diurnal, respiratory, and other rhythms of fetal heart rate in lambs. Am J Obstet Gynecol. 1977 Feb 15;127(4):414–424. doi: 10.1016/0002-9378(77)90500-2. [DOI] [PubMed] [Google Scholar]
  5. Dawes G. S., Fox H. E., Leduc B. M., Liggins G. C., Richards R. T. Respiratory movements and rapid eye movement sleep in the foetal lamb. J Physiol. 1972 Jan;220(1):119–143. doi: 10.1113/jphysiol.1972.sp009698. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Harding R., Johnson P., McClelland M. E., Titchen D. A. Continuous recording of physiological variables and behaviour in young lambs [proceedings]. J Physiol. 1976 Sep;260(2):15P–15P. [PubMed] [Google Scholar]
  7. Hathorn M. K. Analysis of the rhythm of infantile breathing. Br Med Bull. 1975 Jan;31(1):8–12. doi: 10.1093/oxfordjournals.bmb.a071246. [DOI] [PubMed] [Google Scholar]
  8. Kashani M., Haigh A. L. The effects of vagotomy on ventilation and blood gas composition in dog, sheep and rabbit. Q J Exp Physiol Cogn Med Sci. 1975 Oct;60(4):285–298. doi: 10.1113/expphysiol.1975.sp002322. [DOI] [PubMed] [Google Scholar]
  9. Maloney J. E., Adamson T. M., Brodecky A. V., Cranage S., Lambert T. F., Ritchie B. C. Diaphragmatic activity and lung liquid flow in the unanesthetized fetal sheep. J Appl Physiol. 1975 Sep;39(3):423–428. doi: 10.1152/jappl.1975.39.3.423. [DOI] [PubMed] [Google Scholar]
  10. Prechtl H. F., Lenard H. G. A study of eye movements in sleeping newborn infants. Brain Res. 1967 Aug;5(4):477–493. doi: 10.1016/0006-8993(67)90018-2. [DOI] [PubMed] [Google Scholar]
  11. Ruckebusch Y. Development of sleep and wakefulness in the foetal lamb. Electroencephalogr Clin Neurophysiol. 1972 Feb;32(2):119–128. doi: 10.1016/0013-4694(72)90134-4. [DOI] [PubMed] [Google Scholar]
  12. Shirataki S., Prechtl H. F. Sleep state transitions in newborn infants: preliminary study. Dev Med Child Neurol. 1977 Jun;19(3):316–325. doi: 10.1111/j.1469-8749.1977.tb08367.x. [DOI] [PubMed] [Google Scholar]
  13. Widdicombe J. G., Winning A. Effects of hypoxia, hypercapnia and changes in body temperature on the pattern of breathing in cats. Respir Physiol. 1974 Aug;21(2):203–221. doi: 10.1016/0034-5687(74)90095-4. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES